PROPER, r  OF 


r- 


I 


LI  B  R  ARY     OF 


IQ85-I056 


Property  of 

1  C.  EXPERIMENT  STATION 

P^  '-"rirnent  of  Entomology 


t- 


ECONOMIC  ENTOMOLOGY 


FARMIiR    AND    FRUIT-GROWER,  AND 

FOR  USE  AS  A  TEXT-BOOK  IN 

AGRICULTURAL  SCHOOLS 

AND  COLLEGES 


BV 


JOHN    B.   SMITH,  Sc.D. 


Ftofessor  of  Entomology  in  Rulgers  College ;  Entomologist  to  the  Neiv  Jersey  Agricultural 

College  Experiment  Station  and  the  New  Jersey  State  Board  of  Agriculture ; 

President  of  the  Association  of  Economic  Entomologists,  of  the  Brooklyti 

Entomological  Society,  and  of  the  New  Jersey  State  Microscopical 

Society;    Fellow  of  the   American    Association  for  the 

Advancement  of  Science,  etc.,  etc. 


ILLUSTRATED 


PHILADELPHIA 

J.   B.   LIPPINCOTT    COMPANY 


Copyright,   1S96, 

BY 

J.  B.  LippiNcoTT  Company. 


Electrotyped  and  Printed  by  J.  B.  Lippincott  Company,  Philadelphia,  U.S.A. 


C  O  N  T  E  N  TvS. 

r^ART     I. 

STRUCTURE    AND    CLASSIFICATION. 

CHAPTER    I. 

PAGE 

The  General  Structure  ok  Insects ii 

CHAPTER    II. 
liiE  Head  and  its  Api-endages ......      14 

CHAPTER    III. 
Thorax  and  Abdomen 23 

CHAPTER    IV. 
Muscles,  Digestion,  and  Circulation  . 27 

CHAPTER    V. 
The  Respiratory  System 33 

CHAPTER    VI. 
Nervous  System  and  Senses  of  Insects 39 

CHAPTER    VII. 
The  Reproductive  System       .    • 45 

CHAPTER    VIII. 
Growth  and  Metamorphosis 48 


iv  CONTENTS. 

PART    II. 

THE    INSECT    WORLD. 
CHAPTER    I. 

PAGE 

General  Classification 52 

CHAPTER    II. 
The  Thysanura 55 

CHAPTER    III. 

The  Neuroptera  and  Pseudo-Neuroptera 58 

Order  Ephemeroptera 59 

Order  Odonata 60 

Order  Plecoptera 63 

Order  Platyptera 6/; 

Order  Neuroptera 72 

CHAPTER    IV. 
The  Orthoptera 79 

CHAPTER    V. 
The  Hemiptera,  or  Bugs 100 

CHAPTER    VI. 
The  Coleoptera,  or  Beetles     164 

CHAPTER    VII. 
The  Lepidoptera .    240 

CHAPTER    VIII. 
The  Diptera,  or  Flies 327 

CHAPTER    IX. 
The  Hymenoptera 370 


CONTENTS.  V 

PART    III. 

INSECTICIDES,    PREVENTIVES,    AND    MACHINERY. 
CHAPTER    I. 

PAGE 

Predaceous  Insects,  Parasites,  and  Fungous  Diesases  .   .   .    418 

CHAPTER    II. 
Farm  Practice  to  prevent  Insect  Attack 423 

CHAPTER    III. 
Preventives     430 

CHAPTER    IV. 
Insecticides 434 

CHAPTER    V. 
I^Iachinlry 454 


ACKNOWLEDGMENTS. 


The  illustrations  in  this  book  are  derived  as  follows  :  Electro- 
types were  loaned  for  the  purposes  of  the  work  by  the  Agricul- 
tural College  Experiment  Station  of  New  Jersey,  of  figures  Nos. 
4,  5,  6,  7,  II,  13,  14,  15,  28,  29,  30,  32,  34,  35,  36,  37,  38,  39, 
41,  43,  44,  45,  50,  53,  64,  72,  83,  84,  85,  88,  89,  95,  99,  103,  104, 
105,  114,  127,  128,  129,  130,  131,  132,  133,  134,  136,  137,  138, 
142,  143,  144,  146,  147,  149,  157,  158,  160,  161,  162,  164,  166, 
167,  170,  171,  172,  173,  174,  175,  176,  178,  179,  180,  181,  182, 
183,  188,  189,  190.  192,  194,  195,  200,  201,  202,  204,  206,  212, 
214,  216,  217,  218,  219,  221,  222,  225,  227,  228,  229,  230,  231, 
232,  233,  234,  236,  238,  239,  241,  242,  243,  246,  247,  255,  263, 
264,  265,  274,  278,  279,  281,  283,  286,  287,  288,  289,  290,  291, 
296,  297,  298,  299,  300,  307,  314,  321,  332,  333,  334,  341,  342, 
343.  349.  350,  351.  352,  357.  362,  366,  368,  369,  375,  377,  380, 
386,  387,  392,  393,  394,  395,  396,  397,  398,  399,  401,  409,  410, 
411,  412,  413,  416,  417,  418,  419.  424,  425,  426,  430,  432,  434, 
435.  437.  438,  440,  441.  444.  445.  44^,  447-  448,  449,  450,  454, 
455.  457.  458,  459,  460,  461,  462,  463,  464,  465,  466,  467,  468, 
469.  471,  473,  475,  480,  481,  482. 

By  the  courtesy  of  the  Secretary  of  Agriculture  and  of  the 
Division  of  Illustrations  in  the  United  States  Department  of  Ag- 
riculture, electrotypes  were  obtained  for  figures  Nos.  22,  23,  48, 
56,  58,  73.  74.  75.  76,  81,  82,  86,  87,  90,  91,  92,  93,  100,  loi, 
112,  116,  117,  118,  120,  121,  122,  124,  148,  151,  152,  168,  193, 
198,  209,  223,  224,  226,  244,  245,  292,  293,  294,  295,  315,  316, 
318,  339,  340,  358,  360,  363,  364,  365,  371,  374,  376,  383,  389, 
390,  391.  402,  404,  405,  406,  407,  408,  431,  452,  474,  483. 

The  J.  B.  Lippincott  Company  kindly  loaned  the  following 
from  Saunders's  "  Insects  Injurious  to  Fruits"  :  Nos.  55,  59,  60, 
6ia,  65,  79,  80,  94,  97,  98,  102,  109,  125,  159,  165,  169,  191, 
197,  199,  203,  211,  213,  220,  240,  254,  259,  270,  271,   275,   276, 


vui  ACKNOWLEDGMENTS. 

^n,  284,  302,  308,  309,  310,  311,  312,  313,  324,  325,  326,  327, 
328,  329,  330,  331,  337,  338,  347,  353,  354,  367,  372,  373,  400, 
403,  422,  428,  429,  443  ;  and  from  French's  "  Butterflies  of  the 
Eastern  United  States,"  Nos,  253,  260,  261,  262,  268,  269,  273. 

From  Prof  Lawrence  Bruner,  of  the  University  of  Nebraska, 
were  purchased  electrotypes  of  figures  Nos.  i,  26,  31,  33,  42,  46, 
47,  51,  52,  6ib,  62,  68,  70,  71,  96,  107,  no,  115,  139,  140,  141, 
156,  163,  186,  256,  319,  320,  335,  336,  355,  421,  433. 

From  Houghton,  Mifflin  &  Co.,  pubhshers  of  the  "  Riverside 
Natural  History,"  were  purchased  Nos.  12,  17,  77,  78,  106,  177, 
378,  414,  423,  451,  472. 

From  the  Entomological  Society  of  Ontario  electrotypes  were 
obtained  for  figures  Nos.  207,  208,  258,  420,  456. 

From  the  Cornell  Experiment  Station,  through  the  kindness 
of  Mr.  M.  V.  Slingerland,  electrotypes  were  secured  of  figures 
Nos.  40,  119,  145. 

Mr.  G.  C.  Davis,  of  the  Agricultural  Experiment  Station  of 
Michigan,  furnished  stereotypes  of  figures  Nos.  196,  235,  301, 
370,  388,  439. 

Prof  Herbert  Osborn,  of  the  Iowa  Agricultural  College,  kindly 
loaned  for  reproduction  figures  Nos.  108,  356,  382. 

Dr.  Otto  Lugger,  State  Entomologist  of  Minnesota,  supplied 
electrotypes  of  figures  Nos.  280,  427,  442. 

Dr.  F.  H.  Snow,  of  Lawrence,  Kansas,  loaned  for  reproduc- 
tion figures  Nos.  123,  210. 

Mr.  F.  M.  Webster,  of  the  Ohio  Experiment  Station,  per- 
mitted the  reproduction  of  figures  Nos.  205,  237. 

Mr.  A.  D.  Hopkins,  of  the  West  Virginia  Experiment  Station, 
granted  the  same  favor  for  figures  Nos.  384  and  385. 

Dr.  A.  S.  Packard  kindly  supplied  electrotypes  of  figures  Nos. 
16  and  470. 

To  Dr.  G.  Brown  Goode,  Director  of  the  United  States  Na- 
tional Museum,  I  owe  electrotypes  of  figures  Nos.  27  and  381. 

From  Mrs.  C.  V.  Riley  were  purchased  electrotypes  of  figures 
Nos.  Ill  and  361. 

Dr.  J.  A.  Lintner,  State  Entomologist  of  New  York,  kindly 
supplied  an  electrotype  of  figure  No.  282. 

Prof  S.  A.  Forbes  was  equally  courteous  concerning  figure 
No.  187. 


ACKNOWLEDGMEXTS.  ix 

Prof.  C.  P.  Gillette  loaned  for  reproduction  figure  No.  150. 

Mr.  Frank  Sempers,  of  Philadelphia,  kindly  gave  figure  No. 
49. 

Mr.  H.  G.  Hubbard,  of  Washington,  obligingly  loaned  figure 
No.  359. 

Of  the  machinery  illustrated,  an  electrotype  of  No.  476  was 
supplied  by  Mr.  McGowen,  of  478  by  Mr.  William  Stahl,  and 
of  479  by  W.  &  B.  Douglas. 

The  following  are  originals,  and  were  especially  prepared  for 
this  work  :  Nos.  2,  3,  8,  9,  18,  19,  20,  21,  24,  25,  54,  57,  63, 
66,  67,  69,  113,  126,  135,  153,  154,  155,  184,  185,  215,  248,  249, 
250,  251,  252,  257,  266,  267,  272,  285,  304,  305,  306,  322,  323, 
344,  345,  346,  348,  379,  415,  436,  453,  477.  Of  these  original 
figures,  some  are  photographs,  others  are  from  drawings  by  the 
author,  some  are  redrawn,  and  a  few  are  duplications  of  published 
figures  where  no  plates  were  known  to  be  in  existence. 

To  all  who  have  in  any  way  aided  in  the  preparation  of  this 
work,  and  especially  to  Mr.  L.  O.  Howard,  of  Washington,  who 
kindly  read  my  chapter  on  Hymenoptera,  and  Prof.  Lawrence 
Bruner,  who  kindly  read  my  chapter  on  Orthoptera,  I  tender 
my  sincere  thanks. 


INTRODUCTORY. 


Insect  injurj'  to  agricultural  products  amounts  each  year  to 
millions  of  dollars,  and,  as  a  whole,  shows  a  tendency  to  increase 
rather  than  otherwise.  It  is  not  only  the  actual  devouring  of 
plant  tissue  that  causes  loss  ;  the  effect  upon  the  product  may 
be  to  reduce  its  grade,  or  make  it  more  or  less  unsalable  and 
unprofitable.  In  the  competition  for  markets,  the  grower  of 
the  best  will  always  have  an  advantage  ;  first-class  fruits  and 
vegetables  rarely  fail  to  bring  some  profit,  where  low-grade 
products  cannot  be  sold  at  any  price  ;  and  no  fruit  that  is 
wormy,  defaced,  or  otherwise  injured  by  insects  ever  ranks  as 
first-class. 

Progressive  farmers  have  long  been  aware  of  this,  and  the 
science  of  economic  entomology  has  grown  up  in  response  to 
their  demands  for  information  concerning  insect  depredation  and 
for  means  of  protection  against  it.  It  is  a  science  far  from  sys- 
tematized as  yet ;  made  up  of  fragments  published  here,  there, 
and  everywhere,  rarely  complete  in  themselves  and  often  con- 
tradictory as  to  the  remedial  measures  suggested.  There  have 
been  efforts,  more  or  less  successful,  to  compile  books  of  infor- 
mation concerning  the  insects  attacking  certain  crops  or  kinds 
of  crops  ;  but  there  is  not  now  in  existence  any  work  which 
gives  the  agriculturist  and  student  of  economic  entomology  that 
basic  knowledge  that  enables  him  to  recognize  the  nature  of  the 
insect  he  finds  causing  injury,  or  makes  it  possible  to  decide 
what  sort  of  remedies  should  be  applied.  In  other  words,  the 
underlying  facts  upon  which  the  scientific  application  of  remedial 
or  preventive  measures  is  based  are  not  accessible  to  the  very 
class  that  most  needs  them. 

In  this  book  an  attempt  is  made  to  present  these  matters  com- 
pletely enough  to  give  a  foundation  upon  which  further  informa- 
tion may  be  added  ;    for  whatever  changes  may  occur  in  our 


xii  INTRODUCTORY. 

battery  of  insecticides,  the  philosophy  of  their  application  will 
remain  the  same.  To  do  this  it  is  necessary  to  give  an  outline 
of  the  characteristics  of  insects  generally  ;  of  those  features  that 
distinguish  them  from  all  other  animals,  and  of  those  peculiarities 
upon  which  we  must  base  our  hope  of  conquering  them.  Enough 
of  the  structure  is  described  to  show  how  they  are  built  up,  and 
all  the  different  orders  are  referred  to,  so  that  the  intelligent 
reader  may  recognize  at  least  the  group  to  which  a  specimen 
belongs  and  may  be  able  to  determine  whether  or  not  an  injurious 
species  is  in  hand.  The  direct  needs  of  the  agriculturist  have 
been  kept  constantly  in  mind  ;  but  the  effort  has  been  to  give 
also  a  general  information  on  the  subject  of  insect  life,  and  the 
work  should  be  useful  to  students  in  all  save  advanced  college 
courses,  where  technical  or  systematic  studies  outrank  all  others. 


AN  ECONOMIC  ENTOMOLOGY. 


PART    I. 
STRUCTURE  AND   CLASSIFICATION. 


CHAPTER    I. 

THE    GENERAL   STRUCTURE   OF    INSECTS. 

Insects  are  animals  made  up  of  a  series  of  rings  or  segments 
stiffened  by  a  hard  substance  called  chitine,  and  connected  by  a 
membrane  which  allows  of  more  or  less  freedom  of  motion  be- 
tween them  in  one  or  more  directions.  In  this  they  agree  with 
the  worms,  differing  from  them,  however,  in  the  adult  stage,  in 
that  the  segments  are  grouped  into  three  regions  ;  the  head, 
thorax,  and  abdomen,  as  shown  in  the  diagrammatic  sketch  of 
the  grasshopper.  In  the  larval  stage  of  many  insects  these  re- 
gions are  not  well  marked,  and  they  resemble  worms  decidedly, 
but  nearly  always  have  a  distinct  head  and  more  or  less  distinct 
legs.  If  neither  head  nor  legs  are  visible,  the  larvae  are  chunky 
and  maggot-like  or  grub-like,  rarely  long  and  cylindrical.  In 
fact,  we  have  very  few  terrestrial  worms  in  our  country,  and 
most  of  the  so-called  ' '  worms ' '  are  really  insect  larvae. 

As  a  rule,  an  insect  is  made  up  of  thirteen  rings,  counting  the 
head,  and  in  the  larval  stage  they  are  usually  easy  to  make  out, 
especially  in  caterpillars,  which  may  be  abundantly  secured  at  any 
time  during  the  summer.  In  the  adult  they  are  often  more  or 
less  obscure.  Following  the  head  we  have  three  segments  which 
form  the  thorax  or  trunk,  and  these  bear  all  the  organs  of  loco- 
motion in  the  adult.  In  the  larva,  when  organs  of  locomotion 
are  present,  one  pair  of  legs  is  found  on  each  of  these  segments. 


12  AN  ECONOMIC  ENTOMOLOGY. 

Nine  rings  are  assigned  to  the  abdomen,  though  some  of  them 
may  be  modified  into  structures  faciHtating  egg-laying  or  other 
special  purposes.  In  the  adult  no  appendages  of  any  kind,  ex- 
cept ovipositors,  anal  filaments,  or  cerci,  are  found  ;  but  in  the 
larva,  where  there  is  often  no  real  separation  between  thorax  and 
abdomen,  the  latter  may  bear  organs  of  locomotion  which  differ 
in  their  general  appearance  and  structure  from  the  true  legs,  and 
are  therefore  called  "false  feet,"  or  pro-legs.  The  number  of 
these  pro-legs  sometimes  enables  us  to  recognize  the  order  to 
which  a  larva  belongs,  where  it  otherwise  closely  resembles 
another.  For  instance,  all  the  true  caterpillars  are  larvae  of 
Lcpidoptera,  or  butterflies  and  moths,  and  these  never  have 
more  than  four  pairs  of  pro-legs  at  the  middle  of  the  body  and 
one  pair  on  the  last  segment,  making,  with  the  true  legs,  eight 
pairs  in  all.  In  the  larvae  of  the  sawflies,  a  family  of  the  Hymen- 
optera  in  which  the  resemblance  to  caterpillars  is  very  close,  there 
are  at  least  five  pairs  of  pro-legs  at  the  middle  and  one  pair  at 
the  end  of  the  body,  or  no  less  than  nine  pairs  of  legs  instead 
of  eight  as  before. 

No  insect  has  more  than  two  pairs  of  wings,  and  these  are 
attached  to  the  second  and  third  thoracic  segment.  Some  have 
only  a  single  pair,  as  in  the  true  flies,  and  then  they  are  on  the 
second  or  intermediate  segment.  The  prothorax,  or  first  seg- 
ment, never  bears  wings.  Each  thoracic  segment  bears  a  pair  of 
legs,  which  are  themselves  divided  into  joints  or  segments,  and 
their  structure  will  be  described  more  in  detail  later  on. 

This  division  into  three  distinct  regions  and  the  limitation  to 
six  legs  in  the  adult  separate  the  insects  from  crustaceans,  like 
lobsters,  crabs,  shrimps,  and  the  like,  and  from  the  spiders  ;  none 
of  which  have  the  head  separate  from  the  thorax,  while  all  have 
eight  legs  instead  of  six.  An  insect  in  the  adult  stage  is  there- 
fore a  jointed  animal,  the  rings,  thirteen  in  number,  separated 
into  a  head  of  one,  a  thorax  of  three,  and  an  abdomen  of  nine 
segments  ;  moving  by  means  of  three  pairs  of  jointed  legs.  Some 
differences  between  ' '  larva' '  and  ' '  adult' '  have  been  spoken  of, 
and  it  has  been  indicated  thereby  that  at  different  periods  of 
their  lives  insects  are  unlike  in  appearance.  This  branch  of  the 
subject  is  exceedingly  interesting,  and  will  be  treated  more  fully 
in  Chapter  VIII.     It  is  only  necessary  to  say  here  that,  in  speak- 


STRUCTURE    AND    CLASSIFICATION. 


14  AN  ECONOMIC  ENTOMOLOGY. 

ing  of  the  difference  between  larva  and  adult,  reference  is  particu- 
larly made  to  those  forms  in  which  the  two  stages  are  totally 
unlike  each  other  in  appearance.  Some  of  them  resemble  each 
other  throughout  their  entire  life,  and  here  the  term  ' '  nymph ' ' 
is  often  employed  instead  of  larva. 

It  remains  to  say  a  few  words  concerning  the  chitine,  which 
forms  so  large  a  part  of  the  outer  skeleton  or  crust.     This  sub- 
stance is  found  in  insects  and  in  certain  of 
■    ■  the  crustaceans,  and  is  a  flaky,   horny,  or 

shell-like  material  which  may  become  very 
hard,  and  is  impenetrable  to  most  liquids 
not  absolutely  corrosive  in  character.     The 
Section  through  insect     importance  of  this   fact  it  is  necessary  to 

crust,  showing  layers  of  .  .  ,        .  ^    .  ... 

chitine  at  c,  the  cellular  recognize  in  our  Selection  of  insecticides, 
layer  or  hypodermis  at     bccausc  nothing  that  wc  Can  apply  with  any 

h,  and   basal   membrane  r  ^     ^     ^-l         i       ^  •  re    •       ^i 

^j  ^  saiety  to  the  plant  is  sumciently  active  to  eat 

through  or  penetrate  the  outer  skin  into  the 
insect  body  except  under  peculiarly  favorable  circumstances. 
None  of  the  oils  penetrate  it  readily,  even  gasoline,  benzine,  or 
kerosene  being  resisted.  Alcohol,  chloroform,  and  ether  are  also 
unable  to  make  their  way  through  any  but  a  very  thin  coating. 


CHAPTER    II. 

THE    HEAD   AND    ITS   APPENDAGES. 

The  head  of  an  insect  bears  structures  of  great  interest  from 
the  economic  stand-point,  and  of  these  the  mouth  parts  are  the 
most  important.  In  most  cases  a  glance  at  the  structure  of  the 
mouth  gives  a  clue  to  the  food  habits  of  the  species,  and  may 
convict  a  culprit  whose  work  has  been  discovered,  or  determine 
the  character  of  the  remedy  to  be  applied. 

Roughly  speaking,  two  types  of  mouth  structure  are  found  in 
insects, — the  biting  or  mandibulate,  and  the  sucking  or  haustel- 
late ;  though  there  are  modifications  of  both  which  are  somewhat 
intermediate  in  character. 

In  the  typical  "mandibulate"  or  biting  mouth,  the  mandibles 


STKi'CTL'KE    A. YD    Cl.ASSIFICATIOX. 


15 


Fig.  7v 


or  upper  jaws  are  distinct  and  prominent.  They  work  horizon- 
tally, from  side  to  side,  instead  of  vertically,  or  up  and  down,  as  is 
the  case  in  the  higher  animals,  and  their  form  and  general  shape 
often  furnish  an  indication  to  the  character  of  the  species, — that  is, 
whether  it  is  predace- 
ous,  living  upon  ani- 
mal food,  or  whether 
it  is  phytophagous, 
feeding  upon  plant 
tissue.  This  alone,  in 
some  orders,  suffices 
to  tell  us  whether  we 
have  to  deal  with  a 
friend  or  an  enemy. 
If  the  jaws  are  rather 
long,  sharp-pointed, 
with  slender,  sharp 
teeth  on  the  inner  side 
(Fig.  3,  c,  d),  it  may 
be  safely  classed  as 
predaceous  ;  if  they 
are  broad,  stout,  con- 
cave within,  the  edges 
meeting  broadly,  even 
if  toothed,  or  if  they 
are  gouge-shaped 
(Fig.  3,  a,  e),  we  can 
say  with  great  confi- 
dence that  the  species  feed  upon  vegetable  tissue.  Of  course 
some  uncertainty  may  result  in  intermediate  types  (Fig.  3,  b)  ; 
but  the  rule  holds  good  generally,  and  where  it  leaves  a  doubt, 
some  other  character  will  readily  determine  the  question. 

Forming  the  front  of  the  mouth  and  covering  the  base  of  the 
mandibles  is  the  upper  lip,  or  labrum  ;  on  the  inner  side  of  which 
there  is  usually  a  sensitive  structure,  the  epipharyyix,  which  con- 
tains the  organs  of  taste,  and  corresponds  as  nearly  as  may  be  to 
the  palate  in  higher  animals.  It  has  no  special  function  in  feed- 
ing, and  often  seems  to  form  part  of  the  front  of  the  head  itself 

Below  the  mandibles  we  have  a  second  pair  of  jaws  or  fuaxillce, 


Mouth  parts  of  a  mandibulate  insect :  different  types 
of  mandibles  at  a,b,  c,  d,e ;  /,  the  labrum-epipharynx  ; 
g,  h,  types  of  maxillae  ;  the  cardo  at  c ;  stipes,  st ;  sub- 
galea.j^,-  galea  as  marked  ;  palpus  bearer,  ;>/V,-  palpus 
at  mxp ;  lacinia  at  lac  ;  and  digitus  at  dig- ;  i,  the  labium 
with  sub-mentum,  sm,  mentum,  m,  ligula,  lig,  para- 
glossa,/a>-,  and  palpi. 


I 

1 6  ^A"   ECONOMIC  ENTOMOLOGY. 

much  more  complicated  in  structure,  and  made  up  of  a  number 
of  more  or  less  well-marked  smaller  pieces,  which  vary  consider- 
ably in  form  and  shape  according  to  the  food  habits  of  the  insect. 
Attached  to  each  maxilla  is  a  palpus,  or  feeler,  which  often  bears 
organs  of  special  sense,  and  is  probably  used  by  the  insect  to 
recognize  the  character  of  its  food.  In  function  this  maxilla  is 
auxiliary  to  the  mandibles,  which  cut  and  tear  the  food,  and  de- 
liver it  in  coarse  shape  to  the  maxillae.  These  assort  and  break 
it  up  yet  more  to  better  its  mechanical  condition,  and  deliver  it 
to  the  labium,  or  lower  lip,  which  also  takes  part  in  mixing  the 
food.  There  are  great  differences  in  this  maxillary  structure, 
corresponding  to  the  food  habits ;  and  there  may  be  teeth, 
brushes,  or  other  appendages  suited  to  the  requirements  of  the 
insect.  It  is  rarely  necessary  to  study  these  in  detail,  and  Fig.  3 
illustrates  sufficiently  a  typical  form,  with  all  the  parts  named. 

The  labium,  or  lower  lip,  closes  the  mouth  opening  beneath, 
forming  its  floor,  on  which  is  another  sensitive  surface,  the  hypo- 
pharytix,  which  may  be  compared  in  function  to  the  tongue  of 
the  higher  animals.  As  a  rule,  this  labium  is  much  less  complex 
than  the  maxilla,  and  it  may  be  only  a  single  piece  or  plate, 
though,  like  the  maxilla,  furnished  with  a  pair  of  palpi  or  feelers. 
A  typical  labium  is  shown  at  Fig.  3,  and  the  names  of  the  parts 
are  given.  Close  study  shows  that  originally  the  labium  was 
made  up  of  just  as  many  parts  as  the  maxilla,  but  they  have 
grown  together,  in  the  course  of  time,  for  the  more  complete 
closure  of  the  mouth  opening. 

Insects  with  the  mouth  as  above  described,  no  matter  what 
their  feeding  habits,  are  always  susceptible  of  being  poisoned 
through  their  food  ;  that  is,  they  may  be  reached  by  means 
of  stomach  poisons.  Sometimes,  of  course,  they  feed  in  such 
positions  that  we  cannot  apply  the  poison  satisfactorily, — e.g., 
inside  of  plant  tissue  ;  but  this  does  not  alter  their  susceptibility  ; 
it  simply  means  that  we  cannot  take  advantage  of  it. 

Of  the  hatistellate  or  sucking  mouth  there  are  several  varieties, 
functionally  quite  diverse  and  indicating  difference  in  habit. 

Butterflies  and  moths  differ  from  all  other  insects  in  having  the 
mouth  formed  into  a  flexible  tube,  coiled  like  a  watch-spring 
under  the  head  and  between  the  labial  palpi,  which  are  the  only 
visible  mouth  appendages  present.     The  mandibles  have  disap- 


STRUCll.'RE    AXD    CLASSIFICATION. 


17 


peared  entirely,  and  all  the  other  structures  have  been  so  modi- 
fied that  nothing  remains  except  this  flexible  sucking  tube.  I 
use  the  term  "tube,"  although  it  is  not  such  in  reality,  being 
made  up  of  two  hollow  crescents,  more  or  less  firmly  held  to- 
gether, so  that,  practically,  it  serves  all  the  purposes  of  a  complete 
tube.  When  the  insect  feeds  the  tongue  is  extended,  the  muscu- 
lar structure  being  accommodated  in  the  walls  of  each  half  of  the 
tube.  Fig.  4  illustrates  a  section  through  a  butterfly  tongue, 
showing  the  way  in 

which  the  two  parts  '^'  4- 

are  united.  At  its 
tip  there  are  often 
more  or  less  devel- 
oped processes  which 
serve  as  taste  cups, 
and  also  to  assist  in 
gathering  up  the 
minute    globules   of 

nectar.  Section  through  a  butterfly  tongue. 

A  tongue  of  this 
description  indicates  a  type  which  can  never  be  harmful  to  vege- 
tation, because  it  is  not  fitted  for  either  piercing  or  eating  plant 
tissue  ;  but  it  is,  on  the  contrary,  of  direct  use  in  pollenizing 
flowers.  Butterflies  and  moths  are  never  injurious  in  the  adult 
stage,  however  much  their  larvae  may  offend  ;  but  many  are 
especially  adapted  for  pollenizing  certain  flowers.  Thus  the 
"  Hawk-moths,"  with  tongues  five  and  six  inches  in  length,  are 
able  to  reach  to  the  very  base  of  flowers  like  the  petunias,  even- 
ing primrose,  "Jimpson  weed,"  and  many  orchids. 

A  widely  different  type  of  sucking  mouth  is  found  among  the 
"bugs,"  or  Hetniptera.  Here,  instead  of  a  flexible  tube,  there 
is  a  jointed,  rigid  beak  or  rostrum,  made  up  of  either  three  or 
lour  segments,  inside  of  which  run  four  pointed  lancets.  This 
beak  is  not  a  complete  tube,  but  narrowly  open  in  front  and  at 
the  tip,  to  permit  the  protrusion  of  the  lancets.  Insects  with  this 
structure  gain  their  food  by  piercing  the  plant  tissue  and  sucking 
the  juices,  and  such  a  structure  always  leaves  its  possessor  open 
to  the  suspicion  of  being  injurious.  As  a  matter  of  fact,  many  of 
the  Hemiptera  are  really  predaceous  upon  other  insects  ;  but,  as 


yiA'   ECONOMIC   ENTOMOLOGY. 


a  rule,  they  will  bear  close  watching.  One  thing  is  certain,  how- 
ever :  no  insect  with  this  type  of  mouth  structure  can  be  reached 
by  means  of  a  stomach  poison.      Destruction  through  its  food  is, 

therefore,  absolutely  impossi- 
ble,  because  we  cannot  poison 
the  plant  juices  by  any  method 
thus  far  at  our  command.  An 
insect  of  this  kind  is  incapable 
of  eating  any  solid  food  what- 
ever, and  no  matter  how  thor- 
oughly covered  with  a  corro- 
sive poison  the  outside  of  our 
plants  may  be,  it  would  get 
none,  since  it  only  punctures 
the  tissue  without  absorbing 
any  portion  of  the  outer  sur- 
face. Thus  the  determination 
of  the  type  of  mouth  structure 
often  limits  or  decides  the  char- 
acter of  the  remedy  to  be  used 
in  destroying  the  insect. 

Among  the  Diptera,  or  flies, 
we  have  a  number  of  interest- 
the  ing  modifications  of  the  suck- 
ing mouth.  One  series  is  fur- 
nished with  lancets  similar  to 
those  in  the  bugs,  but  more  numerous,  representing  different 
mouth  structures,  and  not  always  carried  into  the  head  itself. 
The  sucking  structure  is  also  quite  different,  and  never  forms  a 
rigid,  jointed  beak.  Mosquitoes  and  horse-flies  are  examples  of 
this  kind  ;  but  gradually  the  lancets  disappear,  and  in  most  of  the 
flies  only  the  sucking  lip,  often  greatly  and  interestingly  developed, 
remains.  The  common  house-flies  and  blow-flies  are  types  of  this 
modified  form,  and  are  capable  of  taking  liquid  food  only,  though 
often  seen  attacking  solids.  If  the  mouth  of  a  fly  be  examined 
under  the  microscope,  there  will  be  seen  at  the  tip  of  the  lip  a 
series  of  deep  grooves,  stiffened  with  chitinous  loops,  and  armed 
with  sharp  projecting  edges.  When  the  fly  wishes  to  feed  on  a 
solid,  it  scrapes  the  surface  by  means  of  these  rasp-like  projec- 


Mouth    parts    of    a    plant-louse 
jointed  beak  ;  b,  the  lancets,  much  enlarged 
c  and  d  illustrate  the  feeler  and  foot. 


STRUCTURE    AND    CLASSIFICATION. 


19 


lions,  securing  a  small  amount  of  fine  shreds  and  scraps.  These  it 
moistens  with  a  drop  of  saliva,  which  has  great  solvent  properties, 
and  then  draws  up  the  mixture  by  means  of  a  sucking  or  pump- 
ing stomach.  Licjuids  are  taken  in  the  same  way,  and  the  insects 
may  be  said  to  lap  as  well  as  suck  their  food.  Flies  as  adults  are 
not  injurious  to  vegeta- 
tion, whatever  may  be  Fig.  6. 
said  of  their  larvie  ;  but 
some  of  those  fitted  for 
piercing,  like  the  mos- 
quitoes, horse-flies,  and 
gnats,  are  often  trouble- 
some or  injurious  to 
stock,  and  occasionally 
render  regions  infested 
by  them  scarcely  habit- 
able for  man. 

The    bees     seem     to 
combine  the  features  of    „.     .  ....  <■      ..u       «  ..    .v. 

Piercing;    mouth  structures   of   a       horse-fly     :    the 
a      biting      and      sucking  sucking  lip  is  omitted.     Much  enlarged. 

mouth  ;    the    mandibles 

being  fully  developed  and  the  labium  greatly  elongated,  that  they 
may  gather  the  nectar  upon  which  they  feed  and  which  they 
store,  even  from  the  deepest  flowers.  This  modification  will  be 
more  fully  described  in  speaking  of  the  bees  themselves. 

All  the  types  of  mouth  structures  above  described  and  figured 
are  derived  from  one  original  form  by  gradual  modifications  of 
the  different  pieces  ;  but  this  can  be  traced  only  in  a  long  series 
of  preparations  from  many  different  families  and  species. 

Next  to  the  mouth  parts,  the  most  important  appendages  of 
the  head  are  the  antennae  or  feelers.  These  are  variable  in  form, 
and  in  certain  orders  their  structure  indicates,  unfaiHngly,  the 
food  habits  of  the  insect.  They  are  made  up  of  a  variable  num- 
ber of  joints,  differing  greatly  in  their  proportion  to  each  other, 
in  their  shape,  and  in  their  functions.  Ordinarily  the  antennae 
are  intended  as  tactile  organs, — that  is,  for  touching,  as  the  com- 
mon name  "feeler"  indicates  ;  but  it  is  very  certain  that  other 
sensory  structures  are  also  located  there.  The  perception  of 
odors,  or  the  sense  of  smell,  is  a  very  important  function,  and 


AN   ECONOMIC  ENTOMOLOGY. 


more  than  likely  there  is  also  a  sense  of  hearing  connected  with 
them.  In  some  of  the  nocturnal  moths  they  are  broadly  feath- 
ered or  pectinated,  much  more  prominently  in  the  male  than  in 
the  female.  It  is  believed  that  the  reason  for  this  is  that  the 
insects  are  compelled  to  find  their  mates  entirely  by  the  sense  of 

Fig.  7. 


Tip  of  the  mouth  of  a  lapping  fly,  showing  the  pseudo-trachea  on  the  inner  face  of  the 
lips.     Much  enlarged. 

smell.  That  it  is  not  food  they  seek  is  proved  by  the  fact  that 
where  these  feelers  are  most  developed  the  mouth  parts  are  often 
entirely  aborted  and  the  insect  takes  no  food  at  all.  Certain 
"carrion  beetles,"  also  nocturnal  in  habit,  are  attracted  for  long 
distances  to  their  food,  and,  even  where  purposely  hidden,  they 
find  it  without  difficulty  ;  proving  that  the  sense  of  smell  alone  is 
used.     It  may  be  convenient  to  consider  here  a  few  of  the  com- 


STRUCTC'RF.    AND    CLASSIFICATION.  21 

mon  types  of  antennal  structure,  which  occur  in  all  insects,  that 
they  may  be  referred  to  hereafter  without  especial  description. 

The  antennae  are  said  to  h&  filiform,  or  thread-like,  when  the 
joints  are  nearly  even  throughout,  cylindrical,  tolerably  equal  in 
length,  and  similar  in  general  appearance.  A  serrate  or  saw- 
toothed  antenna  has  the  joints  more  or  less  triangular  in  shape 
and  so  fitted  that  one  margin  resembles  the  toothed  edge  of  a 
saw.  Quite  frequently  antennae  of  this  type  are  distinctly  flat- 
tened.    From  such  a  serrated  form  we  pass  gradually  into  the 


Fig.  8. 


Antennal  types. — a,  filiform  and  pubescent;  b,  serrate;  c,  singly  pectinate;  d,  bipecti- 
nate;  e,  clavate ;  y,  capitate;  g,  geniculate;  h,  lamellate. 

pectinated  or  comb-toothed  type,  where  the  joints  are  furnished 
laterally  with  processes  of  variable  length.  When  both  sides  of 
the  joints  have  these  processes  the  antenna  is  said  to  be  bipec- 
tinated  or  feathered  ;  when  the  processes  become  very  slender, 
almost  hair-like,  and  exceedingly  numerous,  it  is  said  to  be 
plumose.  A  feeler  is  clubbed,  or  clavate,  when  the  joints  toward 
or  at  the  tip  suddenly  or  gradually  enlarge  to  form  a  more  or 
less  evident  club  or  bulb,  and  this  type  is  widely  distributed  in 
all  the  orders,  a  variety  of  terms  being  in  use  to  indicate  the 
particular  form  of  the  club.  A  lamellate  feeler  has  at  its  tip  a 
series  of  elongate,  flattened  or  leaf-like  joints,  usually  applied 
close  together  to  form  a  solid  mass  that  conceals  and  protects 


y4A^  ECONOMIC  ENTOMOLOGY. 


the  delicate  sensory  structure  on  the  inner  surface.  An  antenna 
is  vioniliform,  or  bead-like,  when  the  joints  are  more  or  less 
spherical  and  set  together  in  such  a  way  as  to  resemble  a  series 
of  beads  on  a  string. 

As  a  rule,  the  antennae  are  straight,  without  break  from  base 
to  tip  ;  but  occasionally  they  are  geniculate,  or  elbowed  ;  tliat  is  to 

say,  there  is  one  very  long 
basal  joint,  the  "scape,"  fol- 
lowed by  a  series  of  smaller 

Fig.  io. 


Fig.  9. 


_                           ,,                      ^      ,  Head  of  wasp,  to  show  regions:  a, 

'^'        iT                             ■o^O'^                'C^  compound    eyes ;    b,    clypeus ;    c,   la- 

Antennal  types:  a,  moniliform  ;  6,  joints  ciliated;  brum;  rf,  mandibles;  6",  ocelli ; /.place 

c,  bristle-tufted;  d,  plumose;  e,  setaceous.  where  antennae  are  inserted. 

segments  set  in  at  right  angles  to  it.  Usually  an  elbowed  an- 
tenna is  also  clubbed  at  the  tip,  and  so  we  divide  the  structure 
into  "a  scape"  at  the  base,  the  "club"  at  the  tip,  and  the 
"  funicle"  embracing  the  intervening  portion. 

The  feelers  may  be  clothed  with  fine,  soft,  more  or  less  dense 
hair,  and  are  then  pubescent ;  or  furnished  with  lateral  hairs  of 
moderate  length  set  in  regularly,  and  are  then  ciliated  or  fringed  ; 
or  they  may  have  single  or  bunches  of  stiff  bristly  hair,  and  are 
then  said  to  be  bristled,  or  bristle  tufted. 

These  are  all  the  movable  appendages  of  the  head,  and  there 
remain  only  the  organs  of  sight,  which  are  perhaps  better  con- 
sidered under  the  heading  of  sense  organs.  It  is  only  necessary 
to  say  here  that  the  compound  eyes  are  often  very  prominently 
developed,  and  that  they  are  usually  set  at  the  sides,  often  form- 
ing the  greater  portion  of  the  head  itself.  The  ocelli,  on  the 
other  hand,  are  always  very  small  structures  ;  in  the  adults,  never 
more  than  three  in  number,  and  quite  variably  arranged. 


STRUCTURE    AND    CLASSIFICATION.  23 

CHAPTER    III. 

THORAX    AND    ABDOMEN. 

The  thorax,  or  middle  region  of  the  body,  is,  as  has  been 
already  stated,  composed  of  three  rings,  termed  in  their  order 
the  pro-,  meso-,  and  metathorax  ;  meaning  fore,  middle,  and 
hind  thorax.  These  rings  vary  greatly  in  their  proportion  to 
each  other  :  it  is  rare  that  they  are  equally  well  developed,  and 
whenever  this  is  the  case  it  indicates  a  low  type  of  insect, — that 
is  to  say,  one  very  little  specialized.  Usually  they  are  grown 
together  to  some  extent,  and  this  tendency  continues  until  we 
find  in  the  flies  and  bees  the  entire  thoracic  region  apparently 
composed  of  one  solid  mass, — the  rings  being  not  at  all  movable 
upon  each  other.  Insects  of  this  type  are  highest  in  the  scale 
and  the  most  specialized.  In  other  orders,  notably  the  Coleop- 
tera,  or  beetles,  the  prothorax  only  is  free  and  well  developed, 
the  two  other  rings  being  united  together  and  not  movable  one 
upon  the  other.  This  forms  a  sort  of  intermediate  type,  and  the 
rank  of  insects  is  determined,  to  some  extent,  by  the  development 
of  this  region  of  the  body. 

If  the  thorax  of  a  grasshopper,  a  beetle,  or  a  wasp  be  rather 
closely  examined,  it  will  be  found  that  it  is  made  up  of  a  large 
number  of  little  pieces,  divided  by  impressed  lines,  and  sometimes 
these  pieces  are  movable  one  upon  the  other.  They  are  called 
sclerites,  and  a  sclerite,  whenever  that  term  is  used,  always 
means  a  solid  piece  bounded  by  impressed  lines,  or  sutures,  as 
they  are  termed.  Perhaps  ' '  seams ' '  better  represents  the  actual 
case  than  "lines,"  because  they  mark  the  places  where  pieces 
have  been  joined  together,  even  if  the  joint  be  now  a  solid  one. 
Though  these  pieces  seem  confused  at  first  sight,  yet  there  is  a 
distinct  plan  in  their  arrangement,  and,  while  it  is  not  necessary 
to  go  much  into  detail,  it  is  well  to  know  at  least  the  regions 
of  the  segments  and  the  terms  applied  to  them.  In  Fig.  11 
will  be  found  an  illustration  of  the  under  side  of  a  beetle,  in 
which  all  the  sclerites  of  that  part  of  the  body  are  named.  Those 
who  wish  a  more  accurate  knowledge  can  compare  a  series  of 


-'4 


AN  ECONOMIC  ENTOMOLOGY. 
Fig.  II. 


maxinaru 


/T7         ^"^'1 
puzbtcs  .  7 

"^   Tv    mqxdi 


A  beetle,  Harpalus  caliginosus,  from  the  under  side,  with  all  the  pieces  named. 


STKl'CTURE    AND    CLASSIFICATION.  25 

insects  with  this  tigure,  and  by  identifying  the  different  pieces 
observe  for  themelves  what  modifications  have  taken  place.  The 
upper  side  is  always  called  the  dorsum,  or  dorsal  surface,  while 
the  under  side,  between  the  legs,  is  the  sternum,  or  breast. 
Laterally,  between  the  sternum  and  the  dorsum  we  find  the 
pleurum,  whicli  is  a  region  rarely  referred  to  in  general  descrip- 
tion. The  "dorsum,"  "  dorsal  surface,"  and  "sternum,"  on  the 
other  hand,  are  terms  of  frequent  occurrence  in  the  literature  of 
economic  entomology,  and  it  is  well  to  know  exactly  what  is 
meant  by  them. 

As  has  been  previously  said,  all  the  organs  of  locomotion  in 
the  adult  insect  are  attached  to  the  thoracic  segments  ;  never 
more  than  three  pairs  of  legs,  one  pair  to  each  segment,  and 
usually  two  pairs  of  wings,  borne  on  the  meso-  and  metathorax. 
The  prothorax  never  bears  wings,  and,  when  only  a  single  pair 
is  present,  as  occurs  normally  in  the  flies,  or  Diptera,  this  is  on 
the  meso-  or  middle  thoracic  segment. 

Of  the  wings,  or  organs  of  flight,  all  that  need  be  said  here 
is,  that  they  are  more  or  less  membranous,  flattened,  and  stiff- 
ened by  "veins"  or  chitinous  rods.  They  vary  greatly  in  char- 
acter, and  must  be  especially  described  for  each  order,  their 
general  structure  being  all  that  it  is  necessary  to  give  here.  In 
their  origin  wings  are  merely  collapsed  sacs, — that  is,  each  is  a 
bladder-like  outgrowth  from  the  body  wall,  that  assumes  definite 
form,  but  remains  filled  with  liquid  until  ready  to  assume  its  final 
shape.  Then  it  is  gradually  distended  to  full  size,  the  liquid  is 
absorbed,  and  the  walls  of  the  bladder  unite  and  become  so 
closely  welded  together  that  it  is  impossible  afterward  to  separate 
them.  The  wing  seems  like  a  single  thin  membrane,  or  horny 
shell,  as  the  case  may  be,  and  the  veins  appear  like  hollow  rods 
or  cylinders,  though  originally  they  were  mere  thickened  grooves 
on  opposite  sides  of  the  distended  bladder.  The  arrangement  of 
the  veins,  or  "  venation,"  is  of  very  great  importance  in  classifi- 
cation, but  needs  no  particular  exposition  here. 

The  legs,  always  six  in  number  in  the  adult,  are  jointed,  or 
made  up  of  a  definite  number  of  parts  or  pieces.  They  are  fixed 
into  the  thorax  at  the  sides  of  the  sternum,  or  between  the  breast 
and  the  sides,  and  are  fitted  into  a  body  cavity  by  means  of  a 
ball-and-socket  joint,  giving  a  great  range  of  motion.     The  ball 


26  AN  ECONOMIC  ENTOMOLOGY. 

portion  belongs  to  the  leg  and  is  called  a  "  coxa,"  and  the  socket 
is  the  "  coxal  cavity."  Attached  to  the  coxa  is  the  "femur," 
or  thigh,  usually  the  stoutest  part  of  the  leg,  and  corresponding 
to  the  same  portion  of  the  leg  in  the  higher  animals,  most  of  the 
muscular  system  being  found  in  it.  It  is  often  strengthened  at 
the  base  by  a  small  supplementary  piece  called  the  ' '  trochan- 
ter,"  which  sometimes  forms  an  intermediate  segment  between 
coxa  and  femur,  and  may  be  even  two-jointed,  as  in  the  parasitic 
Hymenoptera.  At  the  end  of  the  femur  is  attached  the  "  tibia," 
or  shank,  which  varies  greatly  in  structure  according  to  the 
habits  of  the  insect,  being  modified  for  digging,  tearing,  swim- 
ming, clasping,  or  other  special  functions.  It  is  armed  in  many 
ways,  and  becomes  an  index  to  the  life  history  of  the  insect, 
furnishing,  also,  many  good  characters  of  use  in  classification. 
Economically,  it  is  useful  in  that  it  is  a  guide  from  which  we  can 
often  get  an  idea  of  the  kind  of  existence  that  the  insect  leads, — 
whether  it  is  a  digger,  a  swimmer,  or  a  carnivorous  type.  The 
terminal  part  of  the  leg  is  the  "  tarsus,"  or  foot,  and  this  is  also 
jointed, — five  joints  being  usual,  though  variations  frequently 
occur.  The  last  joint  is  armed  with  a  pair  of  claws,  and  between 
them  we  may  have  "pulvilli,"  or  small  pad-like  structures,  by 
means  of  which  flies  and  other  insects  cling  to  smooth  surfaces 
and  are  able  to  walk  back  downward  on  ceilings.  The  differ- 
ences in  the  leg  structure  are  easily  seen  with  a  little  experience, 
and  In  some  orders,  notably  the  Coleoptera,  they  serve  to  divide 
the  insects  into  large  groups  or  series. 

The  abdomen  normally  contains  nine  segments,  but  these  are 
rarely  all  distinct.  As  a  rule,  one  or  more  are  modified  to  form 
sexual  organs  or  appendages,  or  shields,  or  other  accessory 
structures.  It  sometimes  happens  that  the  segments  on  the 
dorsal,  or  upper,  and  ventral,  or  under,  side  do  not  correspond, 
one  part  of  the  ring  being  lost  or  modified.  In  the  adult  the  ab- 
domen never  bears  organs  of  locomotion,  and,  as  a  rule,  no  appen- 
dages of  any  kind,  except  an  ovipositor  in  the  female  of  certain 
groups,  or  a  pair  of  claspers  in  the  male.  In  some  of  the  lower 
orders  it  bears  jointed  filaments  or  appendages  resembling  feelers, 
and  these  are  called  "  cerci."  Only  in  the  lowest  of  all  types  do 
we  find  traces  of  rudimentary  legs  on  the  abdominal  segments, 
indicating  a  relationship  between  the  insects  and  myriapods. 


STRUCTURE    AND    CLASSIFICATION. 


71 


CHAPTER    IV. 


MUSCLES,    DIGESTION,    AND    CIRCULATION. 

Insects  have  no  internal  skeleton  or  bony  structure,  the  body 
wall  serving  for  the  attachment  of  muscles  and  to  protect  the 
inner  organs. 

Cutting  transversely  through  the  thorax  of  an  insect  at  its  mid- 
dle, we  find  the  greatest  portion  of  the  body  cavity  occupied  by 
muscles,  which  are  arranged  in  bundles  attached  to  the  entire 
inner  surface  of  the  body  wall,  proceeding  to  all  the  appendages, 
and  thus  providing  the  power  that  moves  the  animal.  Centrally, 
the  alimentary  canal  occupies  a  part  of  the  body  cavity,  its  size 

Fig.  12. 


Ideal  section  through  an  insect.— a,  alimentary  canal;  h,  heart;  n,  nerve-cord;  s,  stig- 
mata ;  t,  tracheal  tubes  ;  /,  legs  ;  w,  wings. 

depending  considerably  upon  the  kind  of  insect  in  hand.  Just 
below  the  dorsal  surface  is  a  small  tubular  structure,  at  once  the 
heart  and  only  blood-vessel,  while  just  above  the  ventral  surface 
is  a  white,  knotted  cord,— the  nervous  system.  Laterally,  there 
is  an  opening  on  each  side,  from  which  a  ringed  tube  leads  into 
the  body,  dividing  and  subdividing  almost  immediately  into 
innumerable  branches,  and  this  is  the  respiratory  or  breathing 
system.  Frequently  we  find  around  the  alimentary  canal  a  con- 
siderable fatty  mass,  while  everywhere  through  the  insect  body 


28  AN  ECONOMIC  ENTOMOLOGY. 

we  meet  with  a  whitish  or  sHghtly  greenish  Hquid,  much  more 
abundant  in  the  larva  than  in  the  adult  ;  and  this  is  the  blood. 
These  various  systems  are  of  economic  importance,  for  upon 
our  full  understanding  of  some  of  them  depends  the  success  with 
which  we  can  apply  insecticides  of  a  certain  character. 

Perhaps  the  least  important  in  this  view  is  the  muscular  sys- 
tem. It  has  been  stated  that  the  muscles  are  found  in  the  form 
of  bands,  which  extend  from  the  body  walls  to  the  various  ap- 
pendages, and,  of  course,  they  are  numerous  and  strong  in  pro- 
portion to  the  power  required.  Thus,  for  a  leaping  insect  the 
muscles  moving  the  legs  are  very  much  more  developed  than 
they  are  in  an  insect  which  simply  walks  or  runs,  and  in  a  run- 
ning insect  they  are  better  developed  than  in  one  that  simply 
walks  or  moves  slowly.  Where  powerful  appendages  must  be 
moved,  as  for  instance  the  mandibles  or  jaws,  several  bundles 
of  muscles  frequently  converge  to  a  chitinous  point  or  tendon, 
which  in  turn  is  attached  to  the  appendage,  and  thus  a  great 
amount  of  force  is  exerted  at  one  point,  the  muscular  attach- 
ments on  the  body  wall  covering  a  considerable  surface  and  con- 
verging all  their  effectiveness  upon  one  lever  only.  It  is  this 
arrangement  that  gives  some  insects  the  gnawing  power  to  bur- 
row in  the  hardest  woods,  and  to  cut  through  foreign  substances, 
like  lead,  in  order  to  escape  from  captivity. 

Under  the  microscope  it  is  found  that  the  ultimate  structure  of 
insect  muscle  does  not  differ  in  essentials  from  that  of  the  higher 
animals  ;  that  is  to  say,  it  is  made  up  of  narrow  fibres  divided 
into  cells,  and  transversely  striated.  The  voluntary  muscles  of 
insects  are,  therefore,  practically  like  the  voluntary  muscles  of 
the  higher  animals  or  of  men. 

The  digestive  system  is  of  much  more  importance  from  the 
economic  stand-point.  On  a  previous  page  it  has  been  shown 
that  two  general  types  of  feeding  habits  exist,  the  chewing  and 
the  sucking,  and  the  digestive  system  changes  somewhat  as  the 
needs  of  the  organism  vary.  The  mandibulate  type,  in  which 
the  insect  chews  its  food  and  subsists  upon  more  or  less  solid 
material,  will  be  first  considered.  Most  insects  in  the  larval  stage, 
and  sometimes  also  as  adults,  are  voracious  feeders,  seeming 
determined  to  devour  as  much  as  they  can  possibly  contain,  in 
the  shortest  possible  time  ;  and  the  food  is  in  such  cases  rather 


Fig.  t,^. 


Mandible  of  a  carpenter-bee,  with  bundles  of  muscular  fibres  attached,  each  bundle 
converging  to  a  tendon,  and  the  latter  attached  to  a  mandibular  procesb. 


STRUCTURE    AND    CLASSIFICATION.  29 

Fig.  14. 


Digestive  systems  :  of  a  katydid,  at  a;  of  a  grasshopper,  at  b  ;  and  of  a  roach,  at  c.    All 
the  parts  are  named  save  the  thread-like  Malpighian  tubules. 


30 


AN   ECONOMIC  ENTOMOLOGY. 


coarsely  ground  up  by  the  mouth  parts,  and  forced  through  the 
gullet  or  oesophagus  into  the  crop.  The  oesophagus  is  simply  a 
slender  tube,  usually  straight  or  only  a  little  bent,  at  the  mouth 
of  which  salivary  glands  open,  and  the  food,  mixed  with  saliva, 
passes  through  it  into  the  crop.  This  crop  is  a  more  or  less 
muscular,  but  always  distensible  sac,  and  usually  the  largest 
single  organ  in  the  body.  It  is  used,  primarily,  as  a  place  to 
store  food  when  the  insect  has  the  opportunity  of  obtaining  it, 
and  is  capable  of  containing  a  comparatively  enormous  amount 
of  material.  At  its  posterior  end  it  opens  into  a  gizzard,  or 
grinding  stomach,  and  this  receives  the  food  in  small  quantities, 
to  be  further  reduced  and  put  into  better  mechanical  condition 
for  assimilation.  For  this  purpose  it  is  armed  with  a  complicated 
set  of  plates  and  teeth,  not  alike  in  any  two  species,  while  its 
muscular  coatings  are  dense  and  powerful,  giving  great  twisting 
and  grinding  force.  Sometimes  the  gizzard  is  well  developed 
and  prominent ;  but  often  it  is  greatly  reduced,  appearing  as 
little  more  than  a  slight  specialization  of  the  end  of  the  crop. 
Its  development  depends  very  largely  upon  the  character  of  the 
food  and  the  feeding  habits.  Insects  that  eat  indiscriminately  all 
sorts  of  material,  like  roaches  and  crickets,  have  it  best  developed. 
From  this  gizzard  the  food,  now  in  excellent  mechanical  con- 
dition, passes  into  the  true  stomach,  ox  ckylific  ventricle,  receiving 
at  its  mouth  the  secretions  of  the  ccecal  tubes  or  pouches.  This 
secretion  is  digestive  in  character,  like  a  similar  liquid  in  higher 
animals,  and  assimilation  begins  in  this  part  of  the  system.  The 
stomach  varies  greatly  in  length  in  the  different  kinds  of  insects, 
and  as  much  in  relative  size  and  the  strength  of  its  muscular 
coating.  At  its  posterior  end  we  find  the  long  and  slender  Mal- 
pighian  tubules,  which  often  envelop  the  whole  system  in  a  ver- 
itable net-work  of  fine,  thread-like  masses.  These  structures  are 
supposed  to  represent  kidneys  and  to  have  a  similar  excretory 
function.  They  open  at  the  junction  of  the  stomach  with  the 
iletiin,ox  small  intestine,  and  in  this  the  assimilation  or  absorption 
of  food  products  is  completed,  the  remnant  being  forced  into  the 
large  intestine, or  colon,  where  it  is  prepared  for  excretion  through 
the  rectiim.  A  pair  of  glands  near  the  end  of  the  rectum  secretes 
a  mucus,  probably  intended  as  a  lubricant  only. 

The  salivary  glands  vary  in  number,  and  one  or  more  may  be 


STKC'CrUKE    AND    CLASSIFICATION. 


31 


Fig.  15. 


modified  for  special  purposes  ;  as  in  some  of  the  piercing  insects 
like  bugs  or  the  mosquitoes,  where  an  irritant  poison  is  secreted, 
or  in  certain  beetles,  where  the  saliva  has 
both  a  staining  and  a  burning  effect  upon 
the  skin,  or  in  many  larvae,  where  the  se- 
cretion forms  a  silk  when  hardened  by  ex- 
posure to  the  air.  The  anal  glands  may 
be  similarly  modified,  but  much  more 
rarely  than  those  at  the  anterior  end  of  the 
body.  In  the  "Bombardier  beetle"  their 
secretion  volatilizes  suddenly  when  expelled 
into  the  air,  and  forms  a  blue  smoke,  like 
the  discharge  from  a  small  cannon.  In 
Hymenoptera,  including  bees  and  wasps, 
the  secretion  is  poisonous,  and  accessory 
to  the  functions  of  the  sting.  More  rarely 
a  silk  is  produced  from  these  glands.  Taken 
altogether,  the  digestive  system  varies 
greatly  in  length,  being  .sometimes  a 
straight  tube  only,  the  various  portions 
very  incompletely  divided  off.  In  other 
cases  it  is  quite  complex,  coiled  upon 
itself,  the  parts  well  defined,  and  the  sys- 
tem as  a  whole  two  or  three  times  the 
length  of  the  entire  insect,  different  kinds 
of  structure  being  found  in  the  various 
parts.  The  figures  given  herewith  illustrate 
some  of  these  differences. 

In  the  sucking  or  haustellate  type  the 
essential  structure  of  the  alimentary  canal 
and  the  differentiation  of  the  parts  are  much 
the  same.  There  is,  however,  a  great  reduction  in  the  size  of  the 
gizzard,  which  is  very  often  entirely  wanting.  If  present,  the 
armature  is  reduced  to  a  mere  ridging,  or  a  slight,  irregular 
thickening  of  the  walls  of  the  posterior  end  of  the  crop.  In  the 
Lepidoptera  there  is  often  a  peculiar  accessory  pouch,  which 
seems  to  serve  the  purpose  of  a  storage  reservoir,  or  secondary 
crop,  and  this  is  attached  by  a  narrow  neck  to  the  opening  of  the 
true  crop.     In  the  bees  the  crop  is  unusually  elastic,  and  capable 


Salivary  gland  of  the  cat- 
erpillar of  Melittia  ceto, 
modified  for  silk  spinning: 
mandible  of  the  same, 
above. 


32 


AN  ECONOMIC  ENTOMOLOG\. 


of  enormous  distention  compared  with  the  size  of  the  insect,  and 
this  is  to  accommodate  the  honey  collected  by  the  insects  to  be 
carried  into  the  hive. 

In  the  use  of  poisons  acting  through  the  stomach,  the  arsenic, 
which  is  usually  employed,  is  taken  in  with  the  food  and  gener- 
ally carried  into  the  chylific  ventricle  before  it  becomes  effective. 
In  the  crop  the  food  is  generally  too  dry  to  cause  the  necessary 
solution  of  the  caustic  properties  of  the  arsenic,  which  is  neces- 
sarily applied  in  its  least  soluble  form  ;  but  by  the  time  it  has 
passed  through  the  gizzard  and  has  reached  the  stomach,  becom- 
ing moistened  and  mixed  with  the  secretions  that  have  been 
already  mentioned,  it  becomes  active.  Some  insects  are  able  to 
take  a  very  large  quantity  of  poisonous  material  without  injury  ; 
succumbing  only  after  two  or  three  days  to  the  effects  of  a  poi- 
sonous meal.  It  is  probable  that  in  such  cases  the  digestive 
liquids  exercise  a  less  solvent  effect  upon  the  toxic  mixture. 

Ordinarily,  digestion  in  insects  is  exceedingly  rapid.  Among 
caterpillars,  for  instance,  feeding  is  often  almost  continuous,  and 
twenty-four  hours  are  sufficient  to  pass  through  the  entire  diges- 
tive system  food  two  or  three  times  the  weight  of  the  larvae 
themselves. 

Fig.   i6. 


Heart  of  a  stag-beetle,  showing  the  wings  and  chambers  :  at  the  side,  the  interior  of  a 
chamber,  to  show  the  valves. 


Insects  have  no  system  of  arteries  and  veins,  and  only  one  real 
blood-vessel,  which  serves  also  as  the  heart.     This,  as  has  been 


S7'A'CV7('A'/-:    AND    CLASSIFICATION. 


33 


indicated,  lies  just  under  the  back,  and  in  a  cavity  formed  by  a 
series  of  peculiar  triangular  muscles  known  as  the  ' '  wings  of  the 
heart;"  and  these  serve  to  prevent  undue  pressure  upon  it. 
The  organ  is  simply  a  long  tube,  open  at  both  ends,  and  divided 
into  a  variable  number  of  chambers,  into  which  the  blood  is 
admitted  at  the  sides,  at  intervals  along  its  length.  The  heart- 
beat consists  of  a  wave  of  contraction  beginning  at  the  posterior 
end,  forcing  the  blood  forward  and  out  into  the  head.  Some- 
times one  wave  is  completed  before  another  one  starts,  and 
sometimes  two  or  even  three  waves  may  be  on  the  road  at  one 
time.  Sometimes  the  beat  is  exceedingly  sluggish,  and  some- 
times, in  active  insects,  it  is  very  rapid.  After  the  blood  has 
been  forced  out  of  the  heart  it  first  bathes  the  head  parts,  and 
then  makes  its  way  between  the  muscles  and  other  organs  through 
the  body  cavity  and  into  the  appendages.  Part  of  it  bathes  the 
alimentary  canal,  where  it  receives  the  products  of  digestion,  and 
these  are  carried  everywhere  and  assimilated  by  the  various 
tissues,  the  blood  eventually  finding  its  way  back  to  the  heart, 
to  begin  its  journey  anew.  The  fact  that  there  is  no  closed 
system  of  blood  circulation  is  peculiar,  and  in  this  insects  differ 
from  all  the  higher  animals.  It  necessitates  a  very  decided 
modification  of  the  respiratory  or  breathing  system,  and  this 
forms  the  subject  of  the  next  chapter. 


CHAPTER    V. 

THE    RESPIRATORY    SYSTEM. 

The  respiratory  or  breathing  system  of  insects  is  adapted  to 
the  system  of  blood  circulation.  It  is  important  from  the  eco- 
nomic, as  well  as  interesting  from  the  scientific,  stand-point,  for 
upon  this  rests  the  basis  for  the  application  of  contact  insecticides. 

Insects  have  no  lungs,  and  nothing  which  at  all  corresponds  to 
them.  They  have  no  means  of  taking  in  air  at  the  head  or 
through  the  mouth  ;  but  breathe  from  the  sides,  where  there  is  a 
series  of  breathing-pores,  or  spiracles,  through  which  the  air  is 
taken   into  the   body  cavity.     Typically,  one  pair  of  spiracles 

3 


34 


AN  ECONOMIC  ENTOMOLOGY. 


occurs  on  each  body  segment  ;  but  as  a  matter  of  fact  some  of 
the  segments,  especially  in  the  adult,  lose  them,  the  insect  de- 
pending upon  a  more  limited  number  as  the  main  trunks  become 
enlarged.  The  insect  blood  requires  oxygen,  as  in  the  higher 
animals,  and,  as  there -are  no  lungs  to  which  the  blood  can  be 
carried,  it  is  necessary  that  the  air  itself  should  be  taken  to  all 
parts  of  the  body,  and  this  is  accomplished  by  means  of  tubes 
called  trachea.  Tracheae  occur  in  insects,  in  spiders,  and  in 
myriapods,  all  of  which  are,  therefore,  called  "  Tracheates. " 
Spiders  have  eight  legs  instead  of  six  as  in  the  true  insects,  and 
have  the  head  and  thorax  combined  in  one  piece  or  cephalo- 
thorax.  They  have  also  a  decided  tendency  to  the  formation  of 
lung-sacs.  The  "myriapods"  or  "centipedes"  are  more  worm- 
like in  structure,  and  are  furnished  with  many  legs,» — one  or  two 
pairs  on  each  body  segment, — sometimes  exceeding  one  hundred 
in  number. 

One  tracheal  trunk  or  tube  starts  from  each  spiracle,  and  be- 
gins at  once  to  divide  and  subdivide,  sending  its  ramifications 
to  all  parts  of  the  body,  even  to  the  tips  of  all  appendages,  so 
that  air  permeates  every  part  of  the  insect,  and  tracheal  tissue  is 
present  everywhere.  The  structure  of  these  tubes  is  interesting  : 
they  consist  of  a  membranous  cylinder,  stiffened  by  chitinous 
rings  or  spirals,  in  appearance  very  much  like  the  closely-coiled 
springs  in  automatic  shade-rollers.  This  gives  rigidity  to  the 
tubes,  keeping  them  always  open,  while  at  the  same  time  it 
allows  the  utmost  freedom  of  motion.  A  series  of  longitudinal 
tubes  on  each  side  of  the  body  unite  the  main  trunks  from  each 
spiracle,  and  in  some  cases  there  are  transverse  tubes  joining 
the  longitudinal  tracheae.  The  entire  system  is  thus  connected 
in  one  or  two  ways,  and  at  a  pinch  an  insect  is  able  to  get  its  air 
supply  from  one  spiracle  only  and  from  almost  any  part'  of  its 
body. 

Where  so  many  openings  into  the  insect  body  exist  there 
must,  necessarily,  be  some  arrangement  for  protecting  them  and 
preventing  the  entrance  of  foreign  material.  There  is,  therefore, 
a  great  variety  of  sifting  structures,  their  character  depending 
largely  upon  the  habits  of  the  insects.  There  may  be  a  series 
of  teeth  or  spurs  on  each  side  of  a  narrow,  irregular  slit  ;  a  series 
of  hairs  or  bristles  crossing  in  front  of  the  opening  ;  a  covering 


S7'R('CTCKE    .hVD    CLASSIFICATIOX.  35 

Fig.  17. 


Tracheal  tube,  showing  the  structure  and  methods  of  branching. 
Fig.  18. 


Spiracles  and  their  protection. — a,  plate-like  covering  01  white  grubs,  cross-sec- 
tioned at  b,  to  show  how  air  enters;  c,  a  toothed  slit;  rf,  spiracle  set  on  a  teat-like 
process;  d",  conical  spiracle  set  in  a  pit,  protected  by  crossed  hairs  as  shown  at  y  in 
section  ;  g,  lip-like  spiracle  ;  h  and  /,  unprotected  round  or  slit-like  openings. 


Fig.  19. 


Fig.  20. 


Tracheal  gills. — d,  leaf-like  anal  plate  or 
Agrion  ;  b,  thread-like  tuft  of  Corydalus  ;  c, 
plate-like  gill  of  Ephemera. 


Air-bladder  at  end  of 
tracheal  tube  in  Bom- 
bus. 


36  -/^V   ECONOMIC  ENTOMOLOGY. 

shield,  beneath  which  the  air  must  enter,  or  some  other  variety 
of  screen, — all  intended  to  sift  out  of  the  air  the  foreign  particles 
which  might  injure  the  insect.  Yet  it  is  through  these  spiracles 
that  most  of  the  contact  insecticides  must  act,  as  will  be  more 
fully  detailed  hereafter.  In  many  heavy  insects  there  are  at- 
tached to  the  tracheae  numerous  air-sacs  or  bladders,  the  object 
of  which  is  to  reduce  the  specific  gravity  of  the  insect  to  enable 
it  to  fly  more  readily.  A  common  example  is  the  well-known 
"  May-beetle"  or  "June-bug,"  which  has  the  entire  body  cavity 
filled  with  such  little  bladders.  If  one  of  these  beetles  be  watched 
when  it  emerges  from  its  hiding-place  early  in  the  evening,  it 
win  be  noted  that  it  first  crawls  to  the  top  of  some  blade  of  grass 
or  twig,  or  even  upon  a  stone,  and  rests  there  a  few  minutes. 
If  it  be  closely  observed  it  will  be  seen  to  be  pumping  in  air,— 
that  is  to  say,  the  body  pulsates  rapidly,  and  the  abdomen  seems 
continually  to  increase  in  size.  This  is  because  the  insect  is  fill- 
ing the  air-bladders,  and,  as  soon  as  this  has  been  accomplished, 
it  tries  its  wings,  causing  the  preliminary  "whirr"  which  is  so 
familiar  to  the  observer  in  the  early  evening  of  a  June  day.  After 
two  or  three  trials  the  insect  becomes  confident  of  its  ability  to 
sustain  itself,  and  flies  off"  heavily,  with  a  steady  hum.  If  such 
a  beetle  be  found  at  mid-day  and  thrown  into  the  air  it  will  fall 
heavily,  and  will  be  absolutely  unable  to  sustain  itself  in  flight 
until  it  has  had  an  opportunity  to  inflate  its  air-sacs. 

While  the  vast  majority  of  all  insects  are  air-dwellers,  yet  many 
live  underground,  a  very  large  number  in  water,  and  a  consider- 
able percentage  in  decaying  or  excrementitious  matter,  Vy-here 
pure  air  is  very  difficult  or  impossible  to  obtain.  All  sorts  of 
devices  to  enable  them  to  breathe  under  such  conditions  have 
been  developed,  and  in  all  cases  without  any  essential  modifica- 
tion of  the  system.  Underground  dwellers  usually  find  air  suffi- 
cient for  their  needs  in  the  earth  in  which  they  live,  and  the 
development  here  is  principally  in  the  direction  of  more  perfect 
coverings  for  the  spiracles  to  prevent  the  entrance  of  dirt. 

Among  insects  living  in  or  under  water,  or  spending  a  portion 
ot  their  life  there,  we  note  a  great  variety  of  modifications. 
Many  beetles,  and  some  insects  of  other  orders,  have  the  \ving- 
covers  dome-shaped,  and  so  closely  fitted  that  they  are  able  to 
carry  a  little  supply  of  air   between  them  and   the  abdomen. 


STRUCTURE    AND    CLASSIFICATION.  37 

When  this  supply  is  exhausted  of  oxygen,  the  insect  rises  to  the 
surface,  allows  the  drop  of  tainted  air  to  escape,  and  at  the  same 
time  takes  in  another  bubble  of  pure  air.  It  is  then  supplied  for 
another  period,  varying  in  length  in  the  different  species.  Cer- 
tain other  forms  have  the  body  covered  with  very  fine  hair,  so 
dense  that  the  water  cannot  penetrate  it,  and  these  carry  a  thin 
film  of  air  that  surrounds  them  entirely  while  they  are  in  the 
water  ;  they  really  do  not  get  wet  at  all.  This  air  supply  must 
usually  be  renewed  from  time  to  time  ;  but  occasionally  oxygen 
is  absorbed  from  the  water  itself,  and  the  filmy  covering  is  thus 
kept  constantly  purified.  Yet  other  insects  have  their  surface 
so  absolutely  smooth  and  polished  that  the  water  cannot  touch 
it,  and  here  also  a  slight  film  of  air  may  be  carried  about.  There 
are  other  devices  to  the  same  end,  which  it  is  needless  to  special- 
ize, and  we  pass  to  those  insects  that  never  come  to  the  surface 
at  all,  and  yet  secure  a  sufficient  supply  of  oxygen.  These  crea- 
tures are  mostly  larvae,  and  in  them  we  note  the  development  of 
structures  resembling  the  gills  of  fishes  in  function.  That  is,  in 
certain  leaf-like  or  thread-like  appendages  there  are  a  great  num- 
ber of  very  fine  tracheal  tubes  with  very  thin  walls.  Through 
them  the  insect  absorbs  the  oxygen  contained  in  the  water  itself, 
and  we  have  exactly  the  same  process  that  we  find  in  the  fishes, 
except  that  here  air  instead  of  blood  is  brought  into  contact  with 
the  oxygen  in-the  water.  These  gill-like  appendages  vary  greatly 
in  number  and  shape,  but  do  not  differ  in  function,  and  will  be 
further  described  when  necessary  in  connection  with  the  insects 
themselves. 

Yet  another  type  of  structure  is  found  where  the  absolute  con- 
nection with  the  air  really  never  ceases, — that  is  to  say,  the  in- 
sects have  a  rigid  or  an  extensile  tube  attached  to  the  anal  end 
of  the  body,  and  this  they  keep  pointing  above  the  surface  while 
they  walk  about  on  the  bottom  of  the  ponds.  Insects  so  pro- 
vided are  inhabitants  of  shallow  water,  and  the  tubes  rarely  ex- 
ceed an  inch  or  an  inch  and  a  half  in  length.  The  common 
"rat-tailed  larvae, " often  found  in  the  filthiest  of  all  excrementi- 
tious  material,  are  good  examples  of  this  method  of  breathing. 
They  may  be  entirely  imbedded  in  the  pasty  mass  ;  but  the 
tip  of  the  ' '  tail' '  is  kept  above  the  surface  to  enable  them  to 
secure  fresh  air.     Finally,  we  have  those  cases  where  insects  live 


38  AN   ECONOMIC  ENTOMOLOGY. 

in  the  water,  yet  get  all  their  air  from  above  it  without  any  power 
of  storing.  This  is  the  case  with  creatures  like  the  mosquito 
larvae,  which  are  unable  to  breathe  without  coming  to  the  surface. 
They  have  only  a  single  spiracle  at  the  tip  of  the  body,  and  are 
compelled  to  rise  to  the  surface  at  intervals  to  breathe,  and, 
having  done  so,  are  able  to  sustain  Hfe  beneath  it  for  only  a  short 
time  afterward. 

This  much  for  the  general  characteristics  of  the  respiratory 
system  ;  it  remains  to  show  how  it  is  important  from  the  eco- 
nomic stand-point.  It  has  been  previously  said  that  the  insect 
crust  is  of  chitine,  which  is  impervious  to  a  great  variety  of 
ordinarily  penetrating  substances.  It  resists  alcohol,  chloroform, 
ether,  the  light  mineral  oils,  benzine,  turpentine,  kerosene,  and 
other  similar  substances  ;  acetic  acid  penetrates  slowly  and  so 
does  carbolic  acid.  This  accounts  for  the  difficulty  which  we 
find  in  destroying  many  insect  eggs,  for  there  are  no  openings  in 
them  that  are  sufficient  for  the  penetration  of  these  substances, 
and  they  are  unable  to  act  through  the  egg-wall  itself  To  get  a 
liquid  insecticide  to  kill  an  insect  by  contact,  it  must  be  forced 
into  the  body  through  the  spiracles,  or  they  must  be  so  gummed 
or  clogged  as  to  close  them  completely,  thus  preventing  the  in- 
sect from  breathing  at  all.  Kerosene  is  the  most  reliable  of  the 
penetrating  liquids,  and  even  where  the  spiracles  are  well  pro- 
tected this  material  penetrates  into  the  smallest  openings.  It 
has  the  advantage  of  actually  wetting  everything  ;  that  is  to  say, 
it  is  not  repelled  by  small  hairs,  as  globules  of  water  would  be, 
and  therefore,  as  it  really  comes  into  direct  contact  with  them,  is 
enabled  to  work  its  way  through  the  spiracles.  That  is  what 
makes  the  kerosene  so  much  better  than  any  watery  mixtures 
alone  ;  for  whatever  the  material  extracted  by  or  dissolved  in 
water,  it  may  perhaps  be  repelled  by  the  insect  body,  and  never 
have  the  opportunity  of  exercising  an  effect.  The  various  soaps 
act  in  another  way  ;  as  the  moisture  evaporates,  a  film  of  sticky 
or  gummy  material  remains  which  clogs  the  spiracles,  and  thus 
chokes  the  insect  by  depriving  it  of  air.  Soapy  mixtures  also 
wet  and  stick  well  to  insects  through  the  caustics  they  contain, 
and  which  have  the  power  of  cutting  the  repellent  material  of 
their  bodies. 

In  some  kinds  of  insects  the  spiracles  are  so  feebly  protected 


STRUCTURE    AND    CLASSIFICATION.  39 

that  dry  insecticides  penetrate  them  readily,  if  finely  ground  ; 
and  all  such  are  effective  in  proportion  to  their  fine  mechanical 
condition,  enabling  them  to  enter  the  tracheae  through  the  sieve 
of  the  spiracles.  Thus,  sawfly  larvae  or  "  slugs,"  like  the  "  cur- 
rant-worm" and  "  pear-slug,"  succumb  readily  to  dry  hellebore, 
pyrethrum,  or  even  fine  road  dust.  Many  parasites  may  be 
reached  in  this  way,  and  some  animals  and  all  fowls  keep  them- 
selves tolerably  free  from  vermin  by  frequent  dustings.  This  is 
not  the  place  to  go  into  the  eftectiveness  of  insecticides  ;  but  it 
may  be  repeated  that  contact  poisons  usually  act  through  the 
spiracles  only.  Dry  powders  are  effective  in  proportion  to  their 
fineness  and  to  their  peculiar  poisonous  properties  ;  liquids  are 
effective  in  proportion  to  the  thoroughness  with  which  they  are 
applied,  and  to  their  penetrating  or  clogging  characters. 

Caustics  and  chlorides  act  differently,  and  may  actually  corrode 
a  thin  insect  crust.  But  this  matter  also  comes  more  appro- 
priately under  another  heading,  and  will  not  be  further  discussed 
here. 


CHAPTER   VI. 

NERVOUS   SYSTEM    AND   SENSES   OF    INSECTS. 

The  nervous  system  in  insects  consists  of  a  series  of  white 
disks  or  ganglia  lying  on  the  bottom  of  the  body  cavity,  con- 
nected by  a  double  cord  extending  the  full  length  of  the  insect. 
Insects  have  no  true  brain,  as  do  the  higher  animals,  and  the 
ganglion  situated  in  the  head,  which  is  usually  called  "  brain,"  is 
larger  than  the  others  simply  because  of  the  great  number 
of  special  organs — eyes,  antennae,  and  mouth  parts — that  must 
be  innervated  from  it.  In  its  structure  it  is  precisely  like  the 
other  ganglia,  though  in  some  of  the  social  types  there  is  an 
appearance  of  specialization.  Nerve-fibres  start  from  all  ganglia 
in  every  direction,  and  all  parts  of  the  body  are  reached  ;  the 
nervous  system  in  one  direction  being  exceedingly  well  devel- 
oped. In  the  larval  forms  and  in  the  lower  types,  a  ganglion  is 
present  in  every  segment  of  the  body,  including  the  head  ;  and 
thus  each  segment  contains  its  own  nerve-centre,  the  cords  from 


40 


AN  ECONOMIC  ENTOMOLOGY. 


which  are  primarily  sent  out  to  the  organs  and  appendages  lying 
within  that  particular  segment.  In  adults  there  is  a  tendency 
to  a  union  of  the  thoracic  gangUa,  and  in  the  abdomen  two  are 
usually  confluent  toward  the  anal  end  of  the  body.     The  digestive 

system  is  usually  in- 
FiG.  21.  nervated   by   a   spe- 

cial ganglion,  and 
has  its  own,  partly 
distinct  system.  In 
the  higher  insects  the 
thoracic  ganglion  is 
the  most  important 
in  the  body  for  the 
life  of  the  insect,  and 
if  this  be  cut  or 
destroyed  the  insect 
dies  at  once.  Any 
other  ganglion  may 
be  cut  without  pro- 
^  ducing       immediate 

,  ,    .         ,  ,    , .  death,  and  the  brain, 

Nervous  system  of  the  honey  bee  at  a,  and  of  its 

larva  at  b.  usmg  that   term   for 

the  ganglion  con- 
tained in  the  head,  may  be  entirely  removed  without  necessarily 
killing  the  insect  itself 

While,  as  stated,  the  nervous  system  is  well  developed  and  all 
the  organs  are  well  furnished  with  nerve  endings,  yet  it  is  prob- 
able that  insects  are  not  particularly  sensitive.  The  oft- cited 
case  of  the  butterfly  that  was  captured  and  pinned  while  alive, 
then  escaped  from  the  collector,  and  returned  at  once  to  its 
feeding  among  the  flowers  without  apparent  inconvenience,  is 
known  to  most  readers.  If  a  dragon-fly  be  captured  and  held 
by  the  wings  loosely,  so  as  to  prevent  its  escape  but  not  to 
injure  it,  and  the  tip  of  its  abdomen  is  then  presented  to  its 
mouth,  it  proceeds  at  once  to  eat  it  as  far  as  it  can  reach,  with- 
out any  apparent  knowledge  of  what  it  is  doing.  It  will  thus 
devour,  with  the  greatest  portion  of  the  abdomen,  half  its  diges- 
tive system,  nearly  half  its  entire  nervous  system,  and  a  large 
part  of  its  heart ;  yet,  if  it  be  then  released,  it  will  fly  ofl",   little 


STRUCTURE    AND    CLASSIFICATION.  41 

the  worse,  except  that  it  is  unable  to  balance  itself.  Insects  may 
lose  a  considerable  number  of  their  members  without  apparent 
inconvenience  :  a  tly  may  lose  a  leg  or  two  without  seeming 
in  the  least  worried,  or  one  or  both  of  its  wings  may  be  torn  off 
without  causing  death  or  even  a  manifestation  of  pain. 

I  once  made  a  series  of  experiments  to  test,  not  so  much  the 
sensibility  of  flies,  as  the  effect  that  cutting  the  various  organs 
would  exercise  upon  it.  I  found  that  if  I  cut  off  the  abdomen 
completely,  the  fly  would  live  for  twenty-four  hours  thereafter  ; 
with  practically  no  digestive  system,  with  very  little  nervous 
system,  and  with  most  of  its  heart  gone.  Turning  the  matter,  I  cut 
off  the  head,  and  found  that  it  would  live  without  a  head  for  just 
about  as  long  a  time  as  it  would  without  an  abdomen.  Of  course 
death  was  bound  to  result  from  this  mutilation  in  time,  but  the 
interesting  feature  is  that  no  apparent  symptom  of  pain  was 
developed.  I  found,  however,  that  just  as  soon  as  I  cut  the  large 
ganglion  in  the  middle  of  the  thorax  I  terminated  life.  What- 
ever sentimental  feeling  there  may  be  in  the  matter  of  causing 
unnecessary  pain,  there  is  no  reason  to  believe  that  insects  have 
any  well-developed  sensitiveness,  as  we  understand  that  term. 
The  character  of  the  insect  nervous  system  is  so  entirely  different 
from  our  own  that  we  are  left  without  real  guides  in  our  interpre- 
tation of  the  various  sensory  structures.  Man  judges  most  things 
by  himself,  and  where  this  guide  fails  he  is  at  a  loss,  and  cannot 
be  certain  that  he  interprets  what  he  sees  correctly. 

The  eyes  are  perhaps  the  most  prom.inent  and  best  understood 
of  the  organs  of  special  sense.  They  are  of  two  kinds,  simple 
and  compound,  and  both  may  be  present  in  the  same  species. 
The  simple  eyes  are  termed  ocelli,  and  consist  of  a  more  or  less 
convex,  often  bead-like  lens  or  facet,  by  means  of  which  an  image  _ 
is  thrown  on  a  retina,  and  thus  transferred  to  the  perceptive 
centres.  In  larvae  simple  eyes,  or  ocelli,  are  the  rule,  except  in 
types  with  incomplete  metamorphosis,  where  the  eyes  resemble 
those  of  the  adults.  In  larvae  the  simple  eyes  may  be  situated  at 
almost  any  point  on  the  head  ;  but  usually  they  are  grouped  at 
the  sides  :  sometimes  only  a  single  ocellus  at  each  side,  sometimes 
a  group  of  a  dozen  or  more,  forming  the  rudiments  of  a  com- 
pound eye.  In  adults  there  are  rarely  more  than  three  ocelli, 
usually  situated  in  a  triangle  either  close  together  or  widely  sep- 


42 


AA^  ECONOMIC  ENTOMOLOGY. 


arated  ;  or  there  may  be  only  two,  one  on  each  side,  near  the 
base  of  the  antenna,  as  is  usual  in  butterflies  and  moths. 

Fig.  22. 


Sensory  organs  of  insects. — A,  one  element  in  eye  of  a  roach  ;  B,  section  of  compound 
eye  ;  C,  organs  of  smell  in  May-beetles  ;  D,  sense  organs  in  abdominal  appendages ;  E, 
sensory  ear  ;  F,  ear  on  foreleg  of  locust ;  (7,  ear  found  on  the  basal  segment  of  grass- 
hopper abdomen.     .All  greatly  enlarged. 

Compound  eyes  are  so  termed  because  they  are  made  up  of  a 
great  number  of  simple  eyes,  or  ocelli,  set  very  close  together. 
If  the  head  of  a  bee  or  house-fly  is  examined,  it  will  be  noted 
that  the  brown  eyes  occupy  a  very  large  portion  of  its  surface, 
and  if  one  of  those  eyes  be  viewed  under  the  microscope  it 
will  be  found  to  be  faceted,  or  to  consist  of  thousands  of  little 
hexagonal  disks,  resembling  in  appearance  the  top  of  a  honey- 
comb. Each  one  of  these  facets  represents  a  complete  eye, 
capable  of  forming  an  image  upon  its  own  little  retina,  and  the 
combination  of  all  the  little  retinal  pictures  is  what  a  fly  or  other 
insect  sees.  In  some  cases  the  eyes  are  so  enormous  that  the 
in.sect  can  see  everything  going  on  in  front,  at  each  side,  above 
and  beneath,  and  even  back,  except  directly  behind  it.  It  is 
difficult  for  us,  who  are  able   to  see  in  one  direction  only,   to 


STKUCrURK    AND    CLASSIFICATION.  43 

imagine  the  sort  of  picture  an  insect  perceives,  and  we  are  by  no 
means  certain  how  well  or  iiow  poorly  it  really  does  see.  We  know 
only  that  larval  forms  and  low  types,  provided  with  ocelli  only, 
see  very  feebly  and  indefinitely,  and  can  do  little  more  than  dis- 
criminate between  light  and  darkness.  Many  insects  have  no  eyes 
at  all,  living  under  such  circumstances  as  to  make  them  useless. 

That  insects  hear  follows  almost  inevitably  from  the  fact  that 
many  of  them  "sing," — that  is,  produce  some  sort  of  noise. 
What  those  organs  of  hearing  are  is  not  so  certain  in  all  cases, 
nor  where  they  are  situated,  since  we  cannot  confine  our  search 
for  ears  to  the  head  alone.  In  the  Orthoptera  they  have  been 
located  with  a  reasonable  degree  of  certainty  :  in  the  grasshopper 
the  ears  are  on  each  side  of  the  basal  segment  of  the  abdomen, 
while  in  the  locusts  and  crickets  they  are  on  the  anterior  tibiae. 
Essentially,  these  ears  consist  of  a  tense  membrane  stretched  over 
a  cavity,  and  connected  by  means  of  little  processes,  correspond- 
ing somewhat  to  the  bones  of  the  human  ear,  with  a  bulb-like 
vesicle  and  a  large  auditory  nerve.  In  most  other  orders  no 
similar  structures  are  found,  and  the  sense  of  hearing  is  located 
in  the  antenna^,  or  feelers,  of  which  more  will  be  said  later  on. 

Insects  are  able  to  discriminate  as  between  foods,  and  the  sense 
of  taste  is  undoubtedly  developed  to  some  extent ;  but  the  taste 
which  seems  agreeable  to  their  sense  would  be  to  us,  in  many 
instances,  the  vilest  conceivable.  No  true  tongue,  as  this  organ 
e.xists  in  the  vertebrates,  is  found  among  insects  ;  but  on  the  up- 
per side  of  the  lower  lip  there  is  often  a  finely  papillate  surface,  set 
with  little  fleshy  pegs  and  processes  communicating  with  nerve 
fibres,  and  this  represents  the  nearest  approach  to  the  tongue 
of  the  higher  animals.  It  is  called  the  hypopharynx ,  and  is 
not  always  present.  Beneath  the  labrum,  or  upper  lip,  we  often 
find  a  separate,  flat,  similar  piece,  and  this  is  the  epipharynx, 
corresponding  in  function  to  the  palate  of  the  higher  animals. 

Nothing  resembling  a  nose  is  found  among  insects,  and  yet 
the  sense  of  smell  seems  very  highly  developed.  Insects  often 
discover  their  food  with  unerring  certainty,  even  when  concealed 
from  sight.  Among  the  nocturnal  species,  where  sight  can  play 
but  a  small  part  at  best,  the  sense  of  smell  seems  most  highly 
developed,  and  usually  more  in  the  male  than  in  the  female. 
This  is  due  to  the  fact  that  the  males,  as  a  rule,  seek  their  mates, 


44 


AN   ECONOMIC  ENTOMOLOGY. 


and  so  keen  is  this  sense  that  they  discover  the  presence  of  the 
female,  even  when  confined  in  a  breeding-cage,  if  a  window  be  left 
open.  Sometimes  male  wood-borers  will  sit  around  a  spot  on  the 
bark  for  a  considerable  time  awaiting  the  emergence  of  a  female, 
which  their  keen  sense  tells  them  is  fully  developed  and  ready  to 
make  her  way  out.  Carrion  feeders  discover  their  food  when  con- 
cealed from  sight,  and  almost  before  decay  has  set  in.  So  far  as 
we  have  been  able  to  ascertain,  the  olfactory  organs  are  situated 
in  the  antennae,  and  form  small  pits  or  depressions,  from  which 
usually  arise  specialized  hairs,  bristles,  or  pegs,  as  the  case  may  be. 


Fig.  23. 


Sensory  organs  of  insects.—^,  sensory  pittings  in  plant-louse  antenna;;  B,  organ  of 
smell  in  May-beetle;  C,  same  in  wasp;  />,  sensory  organs  in  Termes  flavipes ;  E,  F, 
organs  of  taste  in  a  wasp  ;  G,  organ  of  smell  in  grasshopper  ;  //,  sensory  depressions 
on  the  tibia  of  Te>-mes  ;  /,  terminal  joint  of  antenna  of  an  ant ;  K,  section  through  the 
antenna  of  a  honey-bee,  showing  supposed  olfactory  organs.     All  greatly  enlarged. 

The  sense  of  touch  is  located  popularly,  and  I  think  correctly,  in 
the  antennae  ;  but  it  is  quite  certain  that  tactile  hairs  exist  all  over 
the  body  of  the  insect,  more  developed  in  some  than  in  others, 
and  most,  perhaps,  in  larval  forms.  These  structures  always 
consist  of  specialized  hairs  or  bristles,  and  end  in  a  nerve  cell. 


S'/'RLVrrA'E    AXD    CLASS /J- /CAT/ OX. 


45 


It  is  probable  that  in  the  antennae  we  have  a  sense  of  percep- 
tion which  is  able  to  discriminate  between  atmospheric  vibrations, 
and  in  this  way  the  same  or  similar  structures  may  serve  as  organs 
of  hearing,  smell,  and  touch.  That  is  to  say,  it  is  probable  that 
there  is  no  such  sense  in  insects  as  the  power  to  discriminate 
between  smells,  but  that  each  is  able  to  recognize  certain  definite 
kinds  of  odors  which  do  produce  an  effect  upon  it.  So  it  is  also 
likely  that  only  sounds  of  certain  descriptions  are  recognized, 
and  these  sounds  may  even  be  such  as  the  human  ear  is  not 
capable  of  perceiving.  We  are  far  from  understanding  the  senses 
of  insects,  but  the  above  outline  is  all  that  is  necessary  for  our 
present  purpose. 


CHAPTER    VII. 

THE    REPRODUCTIVE   SYSTEM. 

The  rate  of  increase  among  insects  is  often  very  great.  It  is 
nothing  unusual  to  hear  a  farmer  say  that  on  one  day  his  plants 
were  free  from  insects,  or  nearly  so,  while  a  week  thereafter 
everything  seemed  to  be  swarming.  As  a  matter  of  fact,  this  is 
frequently  due  to  a  failure  to  observe  the  insects  in  the  first  place, 
either  in  the  stage  in  which  they  then  existed  or  on  account  of 
their  small  numbers  ;  but  it  remains  true,  nevertheless,  that  in- 
sects are  often  exceedingly  prolific.  The  number  of  eggs  laid 
by  a  female  often  runs  up  to  one  thousand,  or  even  more,  while 
the  number  of  eggs  within  the  power  of  a  Termite  queen  is  be- 
yond all  calculation.  If  it  were  not  for  their  natural  checks,  in- 
sects would  soon  overrun  the  world.  In  one  year  not  one  green 
thing  would  be  left  on  the  face  of  the  earth,  and  not  one  living 
being  other  than  insects  would  exist.  These  natural  checks  con- 
sist largely  in  sudden  changes  or  abnormally  high  or  low  tem- 
perature, in  unusual  moisture  or  drought,  or  in  a  combination 
of  two  or  more  of  these  factors.  Diseases  often  attack  insects, 
and  genuine  epidemics  occur,  sweeping  off  millions  in  one  stage 
or  the  other.  The  natural  enemies  are  legion  ;  many  vertebrates 
are  largely  dependent  for  their  food  upon  insects,  and  this  is 
especially  true  of  birds  and  reptiles,  some  of  which  subsist  upon 
insects  exclusively.     A  large  proportion  of  the  insects  themselves 


46 


AN   ECONOMIC   ENTOMOLOGY. 


Fig. 


are  predaceous,  and  live  upon  others  of  their  kind  ;  great  num- 
bers are  parasites,  their  prey  being  other  insects  of  all  orders, 
and  in  this  way  forms  that  depend  upon  plant  life  for  their  sub- 
sistence are  kept  within  definite  bounds.  These  bounds,  though 
they  may  vary  from  year  to  year,  never  change  much  except 
where  man  interferes.  This  subject  will  be  touched  upon  in  an- 
other place  more  fully. 

Except  in  rare  instances  insects  are  of  two  sexes,  male  and 
female,  and  we  nowhere  find  among  them  true  hermaphrodites. 
In  the  plant-lice  and  gall-wasps  we  have  apparent  exceptions  ; 
but  these  are  only  apparent. 

In  the  female  the  most  prominent  sexual  organs  are  the  ovaries. 
These  consist  of  two  sets  of  tubes,  one  in  each  side  of  the  abdo- 
men, usually  below  the  digestive  system,  united 
at  their  base  into  one  larger  tube  called  the 
oviduct ;  the  two  oviducts  unite,  just  before 
opening  outwardly,  into  a  single  chamber 
called  the  vagina.  The  vagina  opens  out- 
wardly at  the  end  of  the  body,  sometimes  with- 
out special  modification,  sometimes  by  means 
of  a  flexible  or  extensile  tube,  sometimes  as  a 
long,  rigid  cylinder,  and  occasionally  in  the 
form  of  a  sting.  These  structures,  be  they 
rigid  or  otherwise,  are  always  called  ovipositors, 
and  their  function  is  to  place  the  &^^  into  the 
position  necessary  for  its  best  development. 
Associated  with  this  system  are  a  number  of 
glands,  the  use  of  which  is  either  to  give  a 
sticky  coating  to  the  &%^,  enabling  it  to  adhere 
to  the  leaf  or  other  point  at  which  it  is  laid,  or 
to  supply  a  poisonous  secretion,  where  such  is 
of  development,  with  Hcccssary  lor  dciencc  or  lor  stupefymg  prey. 
nutritive  cells,  WW,  be-  There  is  also  a  little  sac,  attached  by  a  slender 
cIpTade^orovi'duct^;  ^uct  to  the  vagiua,  at  about  the  point  where 
the  two  oviducts  unite.  This  is  the  seminal 
receptacle,  and  in  this  is  received  the  seminal 
from  it  the  eggs  are  fertilized  as  they  pass  from 
the  oviduct  into  the  vagina  on  their  way  through  the  ovipositor. 
In  some  insects  these  receptacles  are  very  large,  especially  where 


Ovarian  tubes  of  one 
side,  in  Polistes,  show- 
ing eggs  in  all   stages 


vag,  vagina. 


fluid  of  the  male 


STUrCTlRE    AXD    CLASSI/-7CAT/0A. 


47 


copulation  takes  place  in  the  fall,  and  the  female,  living  through 
the  winter,  does  not  begin  to  lay  eggs  until  some  time  in  spring. 
The  eggs  have  at  one  end  small  openings  termed  niicropyles^  and 
through  these  the  spermatozoa  find  their  way  into  the  ^^^  to 
fertilize  it.  In  the  ovarian  tubes  a  variable  number  of  cells  are 
developed,  and  these  grow  rapidly,  each  cell  eventually  forming 
an  egg.  The  number  of  tubes  and  the  number  of  cells  in  the 
tubes  vary  within  wide  limits  in  the  different  species.  In  some 
they  are  rigidly  limited,  and  the  insects  are  able  to  lay  only  a 
definite  number  of  eggs ;  in  others  the  cells  are  so  numerous  that 
a  definite  number  seems  unlikely.  Before  the  female  has  been 
impregnated  the  ovarian  tubes  are  \ery  slender  and  occupy  only  a 
little  space  in  the  abdomen.  When  the  eggs  develop,  however, 
the  ovaries  increase  in  size  until,  finally,  the  abdomen  is  almost 
entirely  occupied  by  them,  and  is  often  enormously  distended. 

In  the  male  the  ovaries  are  replaced  by  the  testes,  which  also 
are  more  or  less  coiled  tubular  structures,  and  these  tubes,  like 
the   ovaries,    unite    to- 
gether on  each  side  into  ^^^-  ^5- 
a  larger  tube,  which  in 
turn  are  combined  into 
a  single  organ,  usually 
more  or  less  horny  in 
structure, — the  penis. 

Reproduction  among 
insects  is,  therefore,  in 
its  essentials,  like  that 
of  the  higher  animals. 
The  only  difference  is 
that  as  the  life  period  is 
shorter,  the  eggs  must 
all  be  laid  within  a  defi- 
nite time,  and  they  are 
v&ry  much  greater  in 
number.  It  further 
proves  that  we  have  a 
definite  development  in 

insects  as  in  higher  animals,  and  that  with  them  also,  like  pro- 
duces Uke,— that  is  to  say,  the  product  of  the  €:gg  when  fully  de- 


Male  organs  of  May-beetle. — One  side  only  beyond 
the  ductus  ejaculatorius,  duct,  ejac;  glni.,  mucus 
glands;  ves.  sem.,s^ram2X  vesicles;  vas.  de/.,  vasa 
deferentia. 


48  .'LV  ECONOMIC  ENTOMOLOGY. 

veloped  will  be  like  the  parent  that  laid  it,  and  never  anything 
else.  Insects  are  as  a  rule  unable  to  reproduce  until  they  have 
reached  the  adult  stage,  and  the  few  apparent  exceptions  may 
not  be  real  when  all  the  factors  are  understood.  An  insect,  when 
once  adult,  never  changes  into  one  of  a  different  kind  ;  so  a 
beetle  can  never  change  into  a  cricket,  nor  a  small  fly  into  a 
larger  one. 


CHAPTER  VIII. 

GROWTH    AND    METAMORPHOSIS. 

Insects  grow  only  in  the  larval  stage,  and  moult,  or  change 
their  skin,  every  time  there  is  an  increase  in  size.  As  has  been 
stated,  the  insect  crust  is  rigid  and  inelastic,  and  extension  is 
possible  only  by  the  expansion  of  the  membrane  between  the 
rings.  When  a  growing  insect  reaches  the  extent  of  the  elasticity 
in  its  covering,  a  new  skin  forms  beneath  the  old  one,  and  the 
latter  splits,  allowing  the  newly-clad  and  much  larger  specimen 
to  crawl  out  of  it.  In  this  respect  insects  resemble  crabs,  lobsters, 
and  other  crustaceans. 

The  terms  larva,  pupa,  and  adult  have  been  several  times  used 
in  the  previous  chapters,  and  need  more  explanation.  Most 
insects  undergo,  in  the  course  of  their  life,  a  series  of  changes  or 
transformations,  in  which  their  form,  appearance,  and  habits  are 
often  so  diverse  that  the  different  stages  could  not  be  recognized 
as  belonging  to  one  species  without  definite,  continued  observa- 
tion. These  changes  are  termed  metamorphoses,  and  they 
include  the  egg,  larval,  pupal,  and  adult  stages.  With  few 
apparent  exceptions,  all  insects  begin  in  an  egg  stage,  and  the 
method  in  which  this  egg  is  developed  has  been  already  described. 
In  this  stage,  whether  it  be  long  or  short,  the  creature  is  unde- 
veloped and  quiescent,  except  for  the  changes  going  on  within, 
and  which  do  not  result  in  outward  movement.  In  rare  cases 
the  eggs  are  not  extruded  from  the  body  of  the  insect,  but  fertili- 
zation takes  place  in  the  ovary,  the  larvae  hatching  within  the 
abdomen  of  the  mother. 

From  this  egg  comes  in  due  time  a  larva,  a  minute  creature 


STRUCTURE    AND    CLASSIFICATION. 


49 


which  may  or  may  not  resemble  the  parent  that  laid  it.  Assum- 
ing that  it  does,  it  is  without  trace  of  wings.  It  grows  apace, 
moults  as  often  as  necessary,  and  at  last  attains  very  distinct  wing 
pads.  It  is  now  in  the  pu[)al  stage,  and  with  the  next  moult  the 
wings  become  fully  developed.  It  is  then  adult  and  fitted  to 
reproduce  its  kind.  This  sort  of  metamorphosis  is  said  to  be 
incomplete,  because  there  is  no  inactive  stage,  and  because  there 
is  always  a  close  resemblance  in  all  stages.  The  larvae  are  quite 
usually  termed  nymphs,  and  differ  from  the  adults  only  in  size,  in 
the  absence  of  wings,  and  in  the  undeveloped  sexual  characters. 
A  peculiarity  of  this  method  of  growth  or  moulting  is  worthy  of 
incidental  mention.     When  the  insect  moults,  it  is  not  the  outer 


Fig.  26. 


Moulting  of  a  grasshopper.— o,  nymph  ready  to  change;  b,  the  skin  split  along  the 
back  and  the  adult  emerging  ;  c,  continues  the  process,  and  at  d,  the  adult  insect 
drying  out. 

skin  alone  that  is  aftected  :  all  the  most  delicate  mouth  parts  with 
their  hairs  and  processes  are  cast  and  replaced  by  a  new  cover- 
ing ;  the  lining  of  a  large  proportion  of  the  digestive  system 
is  shed,  and  the  inner  coat  or  surface  of  the  tracheal  tubes  is 
renewed,  so  that  practically  the  insect  gets,  in  part,  a  new  diges- 
tive system  and  a  new  breathing  apparatus,  every  time  it  increases 
in  size.  The  number  of  these  moults  varies  in  the  different  orders, 
and  even  in  species  of  the  same  order.  There  may  be  as  few  as 
three  or  four,  and  there  may  be  twenty  or  more.  We  can  some- 
times modify  the  normal  number  by  changing  the  circumstances 
under  which  the  insects  live.  Thus,  the  larva  of  the  common 
Dermestid  found  in  museum   cases  normally  moults  four  times 

4 


5° 


AN  ECONOMIC  ENTOMOLOGY. 


before  it  is  ready  to  change  to  a  pupa.  I  have  confined  several 
larvse  in  vials,  closed  them  tightly  with  rubber  stoppers,  and  sup- 
plied a  small  amount  of  food.  In  these  dry  vials  larv«  have 
lived  for  months,  in  one  case  more  than  a  year,  and  apparently 
as  a  mere  pastime  they  moulted  at  intervals,  so  that  in  one  vial 
there  were  eight  or  ten  cast  skins,  more  than  doubling  the  ordi- 
nary number  of  changes.  Withal  the  insects  did  not  increase  in 
size,  simply  because  no  more  food  was  supplied. 

Where  the  metamorphosis  is  complete,  there  hatches  from 
the  Q.^%  a  grub,  caterpillar,  slug,  maggot,  or  other  crawling  or 
wormlike  creature,  quite  unlike  the  parent.  Growth  continues, 
as  before,  by  moulting,  until  the  full  size  has  been  attained,  and 
then  feeding  ceases.  The  larva  now  seeks  some  retired  spot, 
sometimes  spinning  a  silken  covering  termed  a  cocoon,  and  then 
changes  to  a  chrysalis  or  pupa.  The  term  chrysalis  is  used  in 
the  butterflies,  where  it  is  free  and  often  prettily  ornamented,  and 
the  term  pupa  in  most  other  cases.  In  this  stage  it  is  inactive 
and  rests  quietly  for  some  time.  The  character  of  the  future  in- 
sect is  usually  more  or  less  clearly  defined,  but  occasionally  it 
resembles  neither  the  larva  that  formed  it  nor  the  adult  insect 
which  is  to  come  from  it.  In  due  time  the  adult  emerges  as  a 
butterfly,  moth,  beetle,  fly,  or  bee,  and  no  trace  remains  of  the 
previous  larval  condition.  Insects  never  grow  after  they  reach 
the  adult  stage,  but  remain  of  exactly  the  same  size  as  when 
first  they  emerged  from  the  pupa.  Thus,  as  has  been  indicated 
in  the  previous  chapter,  large  flies  are  never  the  parents  of  small 
flies,  nor  do  small  flies  ever  grow  to  become  larger  flies. 

This  cycle  of  change  in  an  insect  is  termed  its  life  history,  which 
it  is  sometimes  very  difficult  to  work  out.  Scarcely  two  species 
are  alike  in  habit  during  all  their  lives,  and  a  complete  knowledge 
of  the  full  life  cycle  and  the  habits  in  all  stages  is  essential  to  an 
intelligent  application  of  remedial  or  preventive  measures. 

It  is  often  possible  to  reach  an  insect  easily  in  one  stage,  or  at 
one  period,  where  it  is  naturally  protected  during  all  others.  So 
we  may,  sometimes,  by  a  little  change  in  farm  practice,  or  by 
taking  advantage  of  some  preference  on  the  part  of  the  insect, 
avoid  injury.  To  ascertain  all  these  facts  and  to  suggest  the 
treatment  indicated,  is  the  work  of  the  economic  entomologist. 
Watching  the  transformations  of  an   insect  is  a  delightful  task, 


S  TR  L  X  '7'C  RE    AND    CLASSIFICA  TION. 


51 


and  one  that  can  be  easily  accomplished  in  most  cases  by  any 
one  possessing  a  Httle  patience.  In  leaf- feeding  insects  all  that 
is  necessary  is  to  bring  in  a  supply  of  food  with  the  larva  upon 
it,  and  keep  it  in  a  box  rf  can-e,  renewing  from  time  to  time,  so 
that  fresh  food  may  be  always  available.      In  the  bottom  of  the 

F'iG.  27. 


^^ 


A  breeding-cage  of  the  Riley  pattern. 

box  there  should  be  three  or  four  inches  of  clean  sand  for  the 
benefit  of  those  forms  that  go  underground  to  change  to  a  pupa, 
and  in  due  time  the  caterpillar  or  slug  will,  under  the  observer's 
very  eyes,  change  to  a  butterfly,  beetle,  or  other  insect,  accord- 
ing to  the  character  of  the  larva. 


F>AR1^    II. 
THE   INSECT   WORLD. 


CHAPTER    I. 

GENERAL    CLASSIFICATION. 

Those  structures  which  are  of  economic  importance  and,  in- 
cidentally, those  that  are  used  in  classification  have  been  described 
in  the  first  part. 

Classification  is  the  arrangement  of  the  insects  into  series 
which  are  so  related  to  each  other  that  a  species  never  before 
seen  may  be  recognized,  and  its  place  ascertained  from  certain, 
easily  discernible,  structural  characters. 

Insects  that  agree  in  structure  usually  have  similar  habits,  and 
by  placing  an  example  into  its  systematic  position,  the  probable 
life  cycle  becomes  also  known,  and  its  exact  life  cycle  can  be 
more  easily  and  intelligently  traced  out. 

The  divisions  used  are  orders,  families,  genera,  and  species. 
The  term  sub-  may  be  prefixed  to  either,  to  indicate  a  division 
not  marked  enough  to  claim  full  rank. 

A  species  is  the  ultimate  division,  and  consists  of  individuals 
which  agree  with  each  other  in  appearance,  structure,  and  life 
history,  mating  freely  and  producing  progeny,  which  resemble 
the  parents.  An  assemblage  of  such  species  agreeing  in  generaJ 
characters  forms  a  genus,  and  this  is  a  more  or  less  uncertain 
divi-sion,  depending  somewhat  upon  the  opinion  of  the  systematic 
student.  A  series  of  genera  agreeing  in  form,  structure,  and 
life  history  makes  a  family,  and  families  are  united  into  orders. 

For  the  division  into  orders,  use  is  made  of  wings  and  mouth 
structures  and  of  the  transformations. 

For  convenience  in  ready  classification  the  Linnaean  orders  are 
here  adopted,  though  some  of  them  have  been  properly  sub- 
52 


THE    INSECT   WORLD. 


53 


divided.  The  new  orders  are  referred  to,  however,  in  the  proper 
place. 

Lowest  of  all  are  the  77iysa intra,  ineludinu;^  "bristle-tails," 
' '  spring-tails, "  "  fish-moths, ' '  and  the  like.  They  never  become 
winged  or  develop  even  a  trace  of  wings.  The  mouth  parts  are 
small,  retracted,  usually  formed  for  biting,  but  sometimes  so 
undeveloped  as  to  be  almost  without  type.  The  metamorphosis 
is  incomplete  ;  indeed  there  is  only  a  simple  increase  in  size,  and 
nothing  really  worthy  of  the  term  development.  In  most  cases 
the  abdomen  bears  a  pair  or  more  appendages  at  the  tip,  from 
which  some  of  the  common  names  are  derived. 

Next  come  the  Neiiroptera,  or  nerve-winged  insects.  These 
have  four  well-developed  wings,  membranous,  more  or  less 
transparent,  and  so  crossed  by  numerous  veins  that  they  seem 
reticulated  or  netted  :  from  which  character  they  derive  their 
name,  which  means  nerve-winged.  The  mouth  parts  are  man- 
dibulate,  usually  well  developed,  but  sometimes  almost  obsolete. 
In  its  broadest  sense  the  order  includes  "  May-flies,"  "dragon- 
flies,"  "caddice-flies,"  "white  ants,"  "  stone-flies,"  "  lace-wing 
flies,"  and  the  like.  There  are,  however,  two  types  of  meta- 
morphosis,— one  complete,  the  Neiiroptera  proper,  and  the  other 
incomplete,  the  Pseudo-neiiroptera.  It  is  here  that  most  of  the 
new  ordinal  divisions  have  been  made. 

A  step  in  advance  are  the  Orthoptera,  or  straight-winged 
insects,  such  as  roaches,  crickets,  katydids,  and  grasshoppers. 
They  have  two  pairs  of  well-developed  wings, — the  first  or  ante- 
rior usually  narrow  and  a  little  thickened  or  parchment-like;  the 
second  or  posterior  broader,  plaited  or  folded  like  a  fap  beneath 
the  anterior  pair.  The  mouth  parts  are  formed  for  biting,  and  the 
metamorphosis  is  incomplete. 

The  order  Heiniptera,  or  "half-winged"  insects,  includes  all 
the  true  ' '  bugs  ;' '  and  to  members  of  this  series  only  the  term 
"bug"  is  properly  applied,  according  to  entomological  opinion. 
The  order  is  always  distinguishable  by  the  mouth  structure,  which 
is  haustellate,  and  consists  of  a  jointed  beak,  concealing  two  pairs 
of  slender,  pointed  lancets.  The  metamorphosis  is  incomplete. 
The  term  Hemiptera,  or  "  half-winged,"  is  derived  from  the  fact 
that  in  the  typical  series  the  primaries  are  thickened  at  base  and 
thin  or  membranous  at  tip.     In  it  we  have  such  creatures  as  the 


54 


AN  ECONOMIC  ENTOMOLOGY. 


"chinch-bug,"  "squash-bug,"  and  others  of  equal  note.  The 
term  Homoptera,  or  "similar-winged,"  is  used  for  that  series  in 
which  the  fore-wings  are  uniform  in  texture,  as  in  the  plant-lice 
and  Cicadas. 

The  order  Coleoptera  contains  the  beetles,  and  the  name,  mean- 
ing "  sheath- winged,"  is  due  to  the  fact  that  the  anterior  wings 
are  hard  and  horny,  unfitted  for  flight,  and  used  only  as  a  sheath 
or  covering  for  the  posterior  pair.  The  mouth  parts  are  man- 
dibulate,  and  the  metamorphosis  is  complete. 

An  easily  recognized  order  is  the  Lepidoptera,  or  "scaly- 
winged,"  including  the  butterflies  and  moths.  Here  wings  and 
body  are  covered  with  minute  scales,  easily  rubbed  off  and 
resembling  colored  dust.  The  mouth  parts  are  haustellate,  and 
form  a  coiled  tongue,  which  is  usually  concealed  beneath  the 
head,  but  can  be  readily  extended  at  the  will  of  the  insect.  The 
metamorphosis  is  complete. 

Equally  recognizable  are  the  Diptera,  or  "two-winged"  flies. 
The  single  pair  of  wings  is  characteristic,  and  with  it  are  asso- 
ciated mouth  parts  varying  much  in  type,  but  never  mandibulate 
nor  forming  either  a  coiled  tongue  or  jointed  beak.  The  meta- 
morphosis is  complete. 

The  Hymenoptera,  or  "transparent  winged"  insects,  include 
bees,  wasps,  ants,  and  the  like,  and  stand  at  the  head  of  the 
Class  Insecta.  They  have  two  pairs  of  transparent  wings,  with 
only  a  few  veins  ;  the  posterior  smaller  than  the  anterior.  The 
mouth  parts  are  mandibulate,  but  the  tongue  is  often  developed 
as  a  lapping  organ,  and  sometimes  greatly  enlongated.  The 
metamorphosis  is  complete. 

To  show  the  differences  succinctly  the  following  table  may  be 
of  use  : 

Insects  which  never  become  winged,  have  the  mouth  feebly  developed 

and  the  metamorphosis  incomplete Thysanura. 

All  others  are  winged  : 
With  four  transparent  wings,  which  are  net-veined  and  flat;  mouth 
parts  mandibulate  and  well  developed  ;  the  metamorphosis,  either 

incomplete Pseudo-neuroptera. 

or  complete Neuroptera. 

With  the  fore-wings  narrow  and  somewhat  thickened  ;  the  posterior 
folded  fan-like,  or  plaited ;  mouth  mandibulate ;  transformations 
incomplete Orthoptera. 


THE    INSECT   WORLD.  55 

With  fore-wings  thickened  at  base,  thin  at  the  tip  ;  mouth  parts  form- 
ing a  jointed  beak  ;  transformations  incomplete  •    .    .    .  Hemiptera. 

With  the  fore-wings  uniform  in  texture  ;  mouth  parts  and  transforma- 
tions as  before Homoptera. 

The  fore-wings  are  horny,  and  useless  for  flight,  serving  only  as  a  cov- 
ering for  the  posterior  pair  ;  mouth  mandibulate  ;  metamorphosis 
complete Coleoptera. 

All  the  wings  and  the  body  covered  with  scales  ;  mouth  parts  developed 
into  a  long  coiled  tongue  ;  transformations  complete    Lepidoptera. 

The  wings  transparent,  with  only  a  few  longitudinal  veins ;  mouth 
mandibulate,  the  tongue  formed  for  lapping ;  transformations  com- 
plete     Hymenoptera. 

Two  wings  only  ;  mouth  parts  haustellate  ;  transformations  complete 

DiPTERA. 


CHAPTER    II. 

THE   THYSANURA. 

Spring -tails.  Bristle-tails,  Fish-moths,  etc. 

Under  this  term  are  grouped  a  number  of  lowly  insects  which 
never  become  winged,  and  can  hardly  be  said  to  have  any  real 
transformations.  Most  of  them  are  small,  soft  bodied,  with 
feebly  developed  mouth  parts,  and  live  in  damp  earth,  among 
decaying  vegetable  matter.  Some  live  under  bark  of  dead  or 
decaying  trees,  or  in  decaying  wood,  while  in  rare  instances  spe- 
cies are  found  preferring  dry  and  warm  localities.  Among  those 
that  live  in  damp  places  are  forms  without  eyes,  and  with  no  de- 
veloped tracheal  system,  the  necessary  oxygen  being  absorbed 
through  the  skin  itself  Compound  eyes  are  developed  in  a  few 
in.stances  only,  though  ocelli  are  usually  present. 

Peculiar  to  the  order  are  certain  abdominal  appendages.  In 
some  cases  these  are  in  the  form  of  rudimentary  abdominal  legs, 
indicating  a  relationship  to  the  Myriapods  or  Centipedes  ;  but 
more  often  they  consist  of  bristles  or  filaments  attached  to  the 
anal  segment.  In  the  simplest  form  they  consist  of  long,  many- 
jointed  appendages,  whose  function  may  be  tactile,  similar  to 
that  of  the  antennae. 

A  good  example  of  this  type  is  the  little  creature  known  to 


56 


AN  ECONOMIC  ENTOMOLOGY. 


Fig.  28. 


house-keepers  as  the  "fish-moth,"  or  "silver  fish."     It  is  one 
of  the  few  species  tliat  prefers  a  dry,  warm  locaHty,  and  is  found 

in  cupboards  and  closets,  hiding  in 
crevices,  and  running  rapidly  when 
disturbed.  It  is  about  one-quarter 
of  an  inch  in  length,  oblong,  a  little 
pointed  towards  both  ends,  and  has 
the  body  covered  with  minute,  sil- 
very-white, glistening  scales.  It  is 
one  of  the  largest  species  belonging 
to  the  order,  feeding  upon  starchy 
substances  and  food  remnants.  It 
sometimes  becomes  troublesome  in 
libraries,  gnawing  the  calendered 
surface  of  leaves  and  bindings  and 
defacing  them.  The  insect  can 
scarcely  be  said  to  be  injurious,  but 
it  is  often  annoying,  and  may  be 
driven  out  by  a  free  use  of  pyre- 
thrum  dusted  in  corners  and  crev- 
e^ 

A  much  more  common  type  is  the 
spring-tail,"  so  named  from  the 
fact  that  the  anal  appendages  consist 
of  two  short,  bristle-like  processes, 
arranged  to  enable  the  insect  to  leap 
or  spring.  They  are  normally  bent 
under  the  body,  held  in  place  by  a 
catch-like  organ  until  the  insect  de- 
sires to  move  suddenly,  when  the 
catch  or  spring  is  released,  sending 
the  insect  forward  a  surprisingly  long 
distance.  When  excited  it  progresses  by  a  series  of  rapid  leaps 
of  this  kind,  its  course  being  decidedly  erratic  because  no  two  of 
the  springs  are  made  in  the  same  direction. 

"Spring-tails,"  or  Podurids,  are  found  in  moist  localities, 
wherever  decaying  vegetable  matter  occurs.  In  manure  beds 
they  often  occur  in  millions,  and  on  warm  days  may  come  to  the 
surface  in  astounding  numbers.      I  have  seen  a  forcing  bed  cov- 


Bristle-tail  or  fish-moth  ;  Lepisma  sp. 


THE    INSECT   WORLD. 


57 


ered  nearly  half  an  mch  in  depth  by  a  solid  mass  of  these  little 
creatures  not  one-sixteenth  of  an  inch  in  length.     Frequently  a 


Fig.  29. 


Fig 


Papyrus  species :  showing  spring  curved  under  the  body. 

sudden  rise  of  water  on  meadow  or  bog  land  drives  them  out  of 
their  hiding-places,  and  they  leap  about  on  its  surface  for  a  time 
as  readily  as  they  do  on  land.  I  have  seen,  on  cranberry  bogs 
reflowed  late  in  May,  square  rods  of  the  surface  so  densely  cov- 
ered that  nothing  of  the  water  was  visible. 

They  are  often  found  in  damp  cellars,  on  any  vegetable  matter 
stored  there,  and  are  sometimes  ac- 
cused of  promoting  decay.  In  the 
fields  a  cut  potato  placed  underground 
piay  attract  dozens  of  specimens  that 
feed  upon  the  juices  of  the  raw  sur- 
face, and  they  have  been  therefore  ac- 
cused of  producing  scabby  potatoes. 
They  are  of  all  colors,  but  usually 
slate-gray  or  yellowish,  the  markings 
sometimes  quite  pretty  and  distinct. 

As  a  matter  of  fact,  these  insects 
are  never  injurious.  Healthy  vege- 
table tissue  is  not  attacked  by  them, 
and  their  mouth  parts  are  adapted  for 
feeding  on  soft  or  moist  tissues  only  : 
hence  a  decayed  or  bleeding  spot  at- 
tracts them.  They  are  sure  to  occur  in  manure  and  on  manured 
land,  and  can  be  kept  out  to  a  large  extent  by  using  only  mineral 


A  Podurid,  or  spring-tail,  found  on 
manure  beds. 


58  AN  ECONOMIC  ENTOMOLOGY. 

or  "  commercial"  fertilizers.  In  the  manure  itself  they  are  bene- 
ficial rather  than  otherwise,  hastening  its  decay  by  changing  the 
form  of  the  more  resisting  portions. 

It  sometimes  happens  that,  when  found  associated  with  decay 
or  rot  of  stored  produce,  the  insects  are  accused  of  causing  it ; 
but  they  always  follow  and  never  precede  or  cause  the  diseased 
appearance. 


CHAPTER    III. 

THE  NEUROPTERA  AND  PSEUDO-NEUROPTERA. 

May-flies,  Dragon-fiies,  Stone-flies,  Caddice-flies ,  etc. 

The  old  term  Neiiroptera  comprised  all  insects  with  four  more 
or  less  transparent  wings,  reticulated  or  netted  with  numerous 
longitudinal  and  transverse  veins,  and  the  mouth  parts  formed 
for  biting.  As  thus  defined  the  order  was  easy  of  recognition, 
and,  practically,  the  division  is  convenient  here,  for  nowhere  in 
this  series  are  any  species  injurious  to  field  crops.  We  find 
troublesome  species  among  the  parasites,  and  the  Termites,  or 
"  white  ants,"  are  injurious  under  some  circumstances  ;  but,  as  a 
broad  statement,  subject  to  a  few  exceptions,  it  is  correct  to  say 
that  no  Neuroptera  are  injurious  to  field  crops,  and  no  appre- 
hension need  be  felt  whatever  the  numbers  in  which  they  may 
appear. 

It  was  early  found  that  under  this  term  insects  quite  different 
in  life  habits  were  included,  some  having  complete  and  some  in- 
complete metamorphoses.  The  order  was  then  divided,  the  term 
Fsezido-neiiroptera  being  applied  to  those  forms  in  which  the 
transformations  are  incomplete.  The  division  is  a  good  one  ; 
but,  as  there  is  nothing  in  the  adult  to  indicate  to  the  tyro  the 
nature  of  the  changes  it  undergoes,  it  was  not  always  easy  to  de- 
cide to  which  order  a  given  insect  belonged.  More  recently  the 
series  has  been  yet  further  divided,  and  we  have  now  somewhat 
compact  groups  of  net-veined  insects  which  may  be  recognized 
without  much  trouble.  These  will  be  referred  to  in  order  under 
their  modern  names. 


THE    INSECT   WORLD. 


59 


Fig.  31. 


Order  EPHEMEROPTERA. 

This  order  inckules  what  are  known  as  "May-"  or  "day- 
flies,"  the  names  indicating  either  the 
time  at  which  they  first  appear  or 
the  brief  period  of  their  adult  Hfe. 
"May-flies"  occur  most  abundantly 
during  spring  or  early  summer,  in  the 
vicinity  of  lakes,  ponds,  and  rivers. 
They  are  readily  recognized  by  their 
fragile  body,  terminated  by  two  or 
three  long,  thread-like  appendages,  and 
by  their  large,  frail  wings,  the  posterior 
much  smaller  than  the  anterior.  They 
fly  at  night,  and  are  readily  attracted 
to  light,  dozens  being  often  seen  hov- 
ering around  a  single  street  lamp.  I 
have  seen  bushels  of  them  at  the  base 
of  electric  lights  on  the  banks  of  the 
Ohio,  and  the  shores  of  the  Great 
Lakes  are  sometimes  covered  with 
heaps  six  inches  or  more  in  depth,  so 
that  the  stench  from  the  decaying 
bodies  becomes  nearly  insupportable. 
The  head  is  large,  the  eyes  are  round 
and  prominent,  and  the  forelegs  are 
conspicuously  long  and  stout  ;  but  the 

feelers  are  reduced  to  mere  rudiments,  and  the  mouth  parts  are 
atrophied  and  utterly  useless  for  feeding  purposes. 

In  the  May-flies  we  have  the  survival  of  an  ancient  type,  their 
generalized  structure  indicating  a  low  place  in  the  scale  of -devel- 
opment. The  eggs  are  laid  on  the  surface  of  the  water  and  sink 
gradually  to  the  bottom.  From  them  hatch  narrow,  elongate- 
oval,  more  or  less  flattened  larvae,  furnished  laterally  and  some- 
times at  the  end  of  the  body  with  gill-tufts,  living  in  the  mud 
ooze  of  river  and  lake  bottoms,  under  stones,  or  among  aquatic 
plants.  They  feed  on  all  sorts  of  minute  animal  life,  and  prob- 
ably also  upon  the  low  forms  of  vegetation  on  submerged  stones 
or  sticks.     They  grow  slowly,  moult  frequently,  and  live   from 


Mav-flv  and  its  larva. 


6o  AN  ECONOMIC  ENTOMOLOGY. 

one  to  three  years  in  this  condition.  Wing-pads  gradually 
appear,  and  eventually  the  adults  emerge  and  fly  away,  only  to 
shed  their  skins  once  more  in  the  very  act  of  flight.  I  have  seen 
their  delicate,  pure- white  exuviae  float  about  over  the  Ohio  River 
in  such  numbers  as  to  resemble  a  fall  of  snow.  This  moulting  of 
the  adult  is  peculiar  to  the  Ephemerids,  who  mate  soon  after  it 
occurs,  deposit  their  eggs,  and  before  morning  perish, — their 
life-work  accomplished. 

Not  all  forms  are  so  short-lived,  however,  some  requiring  sev- 
eral days  to  complete  oviposition  ;  but  their  inability  to  feed 
indicates  a  brief  existence  at  best.  The  number  of  species  is  large, 
and  the  number  of  specimens  immense,  indicating  an  active, 
aquatic  insect  life  at  least  as  great  as  that  found  in  the  air  or  on 
the  dry  land.  While  the  larvae  feed  on  smaller  creatures,  they 
are  in  turn  devoured  by  fishes,  who  find  in  them  an  important 
article  of  food,  and  in  this  view  only  are  they  of  any  economic 
importance. 

Order  ODONATA. 

Under  this  head  come  the  dragon-flies,  or,  as  they  are  often 
termed,  "devil's  darning-needles,"  "spindles,"  or  "snake- 
doctors."  Many  superstitious  beliefs  are  connected  with  these 
insects,  and  there  is  a  general  indisposition  to  handle  them,  be- 
cause of  their  supposed  ability  to  sting.  The  insects  are  common 
about  ponds  and  streams,  flying  rapidly  over  the  surface  of  the 
water,  occasionally  darting  down  to  touch  its  surface,  and  delight- 
ing always  in  the  bright  sunshine. 

The  body  is  long  and  slender,  fitted  with  an  enormous  head 
principally  occupied  by  the  eyes,  and  with  two  pairs  of  long  nar- 
row wings,  which  are  similar  in  size  and  appearance.  In  some 
species  there  are  leaf-like  appendages  at  the  end  of  the  abdomen, 
and  these  are  erroneously  supposed  to  be  weapons  of  offence. 
The  legs  are  stout,  clothed  with  spines  and  spurs,  as  well  as  with 
long  claws  at  the  tip.  The  mouth  is  formed  for  biting,  the  man- 
dibles and  maxillae  being  greatly  developed  and  sharp-toothed, 
for  tearing  their  prey. 

They  are,  as  has  been  indicated,  predaceous,  and  capture  their 
food  during  flight,  their  powerful  wings  and  legs  enabling  them  to 
overtake  and  grasp  any  creature  that  comes  within  the  range  of 
their  huge  eyes.     Flies  and  mosquitoes  are  the  usual  victims,  and 


THE    INSECT    WORLD. 


6i 


hence   the  term    "mosquito  hawk"   has   also  been  apphed   to 
them. 

It  has  been  suggested  that  dragon-flies  might  be  artificially 
propagated  to  lessen  the  mosquito  pest ;  but  this  is  not  feasible, 
because  they  fly  only  during  the  day,  while  the  mosquito  is 
decidedly  more  a  creature  of  the  night.  No  dragon-fly  volun- 
tarily remains  in  woods,  except  along  streams  and  in  open  glades, 
yet  here  mosquitoes  lurk  by  the  million.  The  proposition  looks 
well  at  first  sight,  but  is  not  practical. 

KiG.  32. 


Draguii-fly  arnl  its  ile\  clopment.  —  Lar\a  ami  pupa  feeding  at  i  and  3;  2,  nymph  ready 
to  change  ;  4,  a  pupa  skin  from  which  5,  the  adult,  has  emerged. 

The  early  stages  are  passed  under  water,  and  the  larvae  are 
ugly  creatures,  somewhat  resembling  the  adults,  but  without 
wings.  They  move  sluggishly  among  the  aquatic  vegetation,  or 
on  the  mud  of  the  bottom,  strongly  resembling  the  latter  in 
color.  They  do  not  swim  readily,  but  some  are  able  to  propel 
themselves  by  drawing  into  the  posterior  part  of  the  digestive 
tract  a  quantity  of  water  and  then  expelling  it  forcibly.  This 
process  really  answers  a  double  purpose,  for  this  same  tract  is 
supplied  with  numerous  fine  tracheal  tubes  through  which  oxygen 
is  drawn  from  the  water  :  two  functions,  respiration  and  locomo- 
tion, being  thus  curiously  combined.  Respiration  is  also  carried 
on  by  means  of  leaf-like  anal  appendages,  in  which  trachea  ramify 
in  all  directions,  forming  gill-like  structures.  As  the  larvae  grow, 
wing-pads  appear,  and  when  these  are  fully  developed  the  pupal 
stage  has  been  reached  ;  the  insects  continuing  active,  however. 


62 


AN  ECONOMIC  ENTOMOLOGY. 


until  ready  for  the  change  to  the  adult.  Then  they  crawl  up  the 
stem  of  some  water  plant,  or  upon  a  projecting  stone,  and  soon 
the  skin  splits  and  the  imagos_emerge.  A  few  minutes  suffice  to 
harden  and  dry  the  newly-developed  adults,  then  with  spread 
wings  they  sail  away  on  a  new  career,  in  a  new  medium. 

In  habit  the  larvae  are  as  predaceous  and  voracious  as  the  adults, 
and  their  prey  consists  of  any  aquatic  forms  which  they  can  cap- 
ture,— mosquito  larvae  forming  quite  a  staple  article  of  diet.  It 
has  been  already  indicated  that  they  are  not  very  active' creatures, 
and  prey  is  captured  by  simply  waiting  in  the  mud  or  on  a  mossy 
stone  until  it  comes  within  reach.  Their  color  renders  them 
almost  invisible  under  such  conditions,  and  nature  has  furnished 
a  remarkably  extensile  mouth  structure,  by  means  of  which  they 
are  able  to  reach  out  some  distance  and  seize  whatever  creature 
may  be  passing  near.  It  is  the  labium,  or  lower  lip,  that  is 
modified  for  this  purpose,  and  is  supplied  with  a  double  hinge 
which  can  be  straightened  out  rapidly  to  bring  into  play  a  pair  of 
large,  slender,  and  pointed  jaws  at  its  tip.  When  this  structure  is 
retracted  it  is  invisible,  covering  the  other  mouth  parts  entirely  and 
hiding  them.  The  term  ' '  mask' '  has  therefore  been  applied  to  it. 
Oviposition  varies  with  the  species,  and  is  interesting.  The 
sexes  pair  during  flight.  The  male  has  the  organs  of  copula- 
tion at  the  base  of  the  ab- 
^^'  domen,  while  the  opening 

of  the  testes  is  at  the  tip. 
Before  pairing  he  fills  the 
seminal  pouch  at  the  base 
of  the  abdomen,  then  grasps 
the  female  by  the  neck  with 
a  pair  of  anal  claspers,  and 
she  curves  up  the  tip  of 
her  abdomen  into  contact 
with  the  opening  to  the 
seminal  duct  of  the  male. 
As  the  eggs  are  fertilized 
the  pair  descend  to  the 
surface  of  the  water,  the 
female  drops  a  little  mass  upon  the  surface,  and  copulation  is 
resumed,  the  process  being  repeated  until  all  the  eggs  are  laid. 


A  species  of  v4^r/o«  and  its  larva;  the  latter  with 
anal  gill-tufts. 


THE    INSECT    WORLD. 


63 


In  some  species  the  female  when  impregnated  crawls  under 
water,  down  the  stem  of  some  aquatic  plant,  and  lays  her  eggs 
on  stones,  plants,  or  even  in  the  mud.  By  folding  the  wings 
backward,  close  to  the  body,  a  film  of  air  is  gathered  which  keeps 
the  insect  dry  and  supplies  it  with  a  sufficient  amount  of  oxygen 
for  a  temporary  return  to  its  old  medium. 

The  order  contains  no  injurious  species,  because  all  are  pre- 
daceous  ;  but,  on  the  other  hand,  none  are  markedly  beneficial, 
because,  though  they  devour  an  enormous  number  of  other 
insects,  these  are  not  usually  species  destructive  to  farm  crops. 

Order  PLECOPTERA. 

The  ordinal  term  signifies  "plaited  wing,"  and  is  used  because 
the  hind  wings  are  longitudinally  folded  or  plaited  beneath  the 


Fig.  34. 


stone-fly,  Perla  bicandata.  and  its  larva. 


anterior  pair,  which  rest  flat  upon  the  back.     The  insects  them- 
selves are  called  "stone-flies,"  and  are  loosely  jointed,  flattened, 


64  AN  ECONOMIC  ENTOMOLOGY. 

the  thoracic  parts  large  and  not  closely  united,  the  wings  exceed- 
ing the  abdomen  in  length.  In  texture  they  are  rather  soft,  and 
the  antennae  are  long  and  many-jointed.  They  frequent  the 
margins  of  streams  and  running  ditches,  preferring  damp,  shady 
localities.  The  mouth  parts  are  mandibulate,  but  their  food 
habits  are  not  well  known.  They  are  not  injurious,  and  are 
economically  important  only  as  food  for  fishes.  The  eggs  are 
laid  in  masses  upon  the  surface  of  the  water,  through  which  they 
sink  to  the  bottom.  The  larvae  are  flattened,  live  among  and 
under  stones,  feeding  upon  vegetation,  and  probably  also  upon 
such  small,  soft-bodied  creatures  as  come  in  their  way.  The  legs 
are  well  developed  and  of  nearly  equal  size.  The  antennae  are 
long  and  slender.  There  are  usually  slender,  hairy  appendages 
at  the  end  of  the  abdomen,  and  on  the  under  side  are  tufts  of  gill- 
like structures  serving  for  respiration.  In  some  species  these 
gills  persist  even  in  the  adult,  forming  a  remarkable  exception  to 
the  general  rule  that  adult  respiration  is  through  spiracles  only. 
One  natural  family    the  Perlidce,  comprises  the  entire  order. 

Order  PLATYPTERA. 

The  ordinal  term  signifies  "flat  winged,"  or  "  broad  winged," 
and  in  those  forms  in  which  wings  are  present  the  secondaries 
are  not  folded  or  plaited,  but  lie  flat  over  the  body,  covered  by 
the  primaries.  The  mouth  parts  are  mandibulate,  the  thoracic 
rings  are  loosely  jointed,  and  as  a  rule  the  insects  have  a  flattened 
appearance.  In  most  cases  the  head  is  large  and  prominent, 
wider  than  the  thoracic  rings. 

Three  distinct  families,  using  that  term  loosely,  are  grouped  in 
this  order,  diflering  greatly  from  each  other,  all  of  some  economic 
importance,  and  requiring  more  detailed  consideration. 

Family  termitid^. 
Termites,  or  "white  ants,"  as  they  are  called,  from  their 
appearance  and  habits,  occur  all  over  the  United  States,  but  are 
more  common  southward.  They  are  separated  as  a  distinct 
order  under  the  term  Isoptera,  meaning  similar-winged,  and  are 
interesting  from  their  social  organization,  which  is  complicated, 
several  forms  or  castes  existing  in  each  colony.  All  our  species 
live  in  and  feed  upon  woody  or  fibrous  material,  though  extend- 


THE    INSECT   WORLD. 


65 


ing  their  galleries  through  the  soil,  often  for  great  distances,  and 
also  inhabiting  underground  chambers. 

In  woodland  almost  any  log  or  decaying  tree  will  be  found 
swarming  with  these  dirty  yellowish-white  insects,  about  one- 
fourth  of  an  inch  long,  readily  recognizable  by  their  large  heads 
and  oval,  obtusely- 
terminated  abdomen.  Fig.  35. 
They  are  wingless,  and 
when  exposed  to  light 
seek  at  once  to  make 
their  way  back  into 
darkness.  These  are 
workers,  and  blind ; 
they  never  voluntarily 
come  out  of  their  gal- 
leries, all  their  wander- 
ing being  in  tunnels  of 
enormous  length  run 
over  or  under  ground 
in  every  direction  from 
the  main  nest.  If  they 
must  reach  a  point 
to  which  they  cannot 

burrow,  they  build  a  covered  way  of  earth  mixed  with  saliva, 
woody  and  excrementitious  matter.  These  workers  are  the  most 
familiar  to  the  casual  observer,  and  form  much  the  greater  pro- 
portion of  the  inhabitants  of  a  nest  or  colony.  They  have  distinct, 
hard,  brown  mandibles,  not  excessive  in  size,  and  can  be  thus 
readily  distinguished  from  the  soldiers,  which  are  larger,  with 
proportionately  larger  heads  and  very  largely  developed  mandi- 
bles. The  soldiers  form  a  standing  army  whose  duty  it  is  to 
protect  the  community  ;  therefore,  if  we  disturb  a  colony  the 
workers  at  once  run  away,  leaving  the  field  to  the  soldiers,  who 
are  impotent  enough  in  the  daylight,  blindly  gnashing  their  jaws  ; 
but  are  no  doubt  useful  in  the  ordinary  routine  of  Termite  life. 
Early  in  spring  we  find,  in  addition,  larger,  winged  individuals, 
chestnut-brown  in  color,  and  these  are  the  true  sexed  forms, 
male  and  female.  On  a  bright,  warm  day,  when  spring  is  well 
advanced,   these   individuals,   which   by  the   bye   are  furnished 

5 


Ttrmes fiavipes. — a,  larva;  b,  winged  male;  c,  worker; 
d,  soldier:  e,  female;/",  pupa. 


66  AN  ECONOMIC  ENTOMOLOGY. 

with  eyes,  leave  the  parent-nest  in  great  numbers  and  fly  about, 
enjoying  for  a  few  brief  hours  the  sun  and  air.  They  are  then 
said  to  be  "swarming,"  and  select  their  mates,  returning  to  the 
surface  before  the  setting  of  the  sun.  Out  of  the  vast  numbers 
leaving  the  nest  few  survive  the  day  of  flight.  They  have  numer- 
ous enemies,  and,  even  if  they  escape  these,  must  depend  upon 
being  found  and  adopted  by  some  vagrant  workers  before  they 
are  able  to  form  a  colony.  The  sexed  individuals — king  and 
queen — are  helpless,  can  do  nothing  for  themselves,  and  are  not 
permitted  to  return  to  their  old  home.  This  serves  to  keep  the 
insects  in  check,  for  the  chances  of  starting  a  new  colony  are 
very  small.  Let  us  assume,  however,  that  a  pair  is  adopted  and 
housed,  the  workers  at  once  building  a  proper  habitation  for  the 
royal  pair.  Reproduction  begins  immediately,  and  the  female, 
now  stripped  of  wings  by  her  own  act,  gradually  enlarges,  the 
abdomen  ultimately  becoming  a  mere  egg-sac.  Such  a  queen 
becomes  the  mother  of  the  colony,  and  she  is  tolerably  prolific  : 
sixty  eggs  a  minute  have  been  counted,  making  a  possible  output 
of  over  eighty  thousand  in  a  single  day  !  The  workers  take  entire 
charge  of  the  eggs  and  resulting  young,  feeding  and  tending 
them  until  they  are  able  to  take  part  in  the  ordinary  work  of  the 
colony.  Both  males  and  females  are  represented  among  the 
larval  forms,  but  it  seems  to  depend  entirely  upon  the  nurses  as 
to  what  caste  is  to  result.  They  are  able  at  will  to  arrest  devel- 
opment and  to  produce  whatever  forms  are  needed  in  the  com- 
munity. Thus  workers  and  soldiers  are  each  of  both  sexes,  but 
the  sexual  organs  never  become  developed  or  functional.  A 
certain  proportion  are  allowed  to  develop  fully,  and  these  furnish 
the  annual  swarms.  If  the  queen  becomes  old  or  unable  to  sup- 
ply the  colony  with  a  sufficient  number  of  young,  the  workers 
provide  for  a  number  of  "  complemental"  males  and  females. 
These  never  become  winged,  reaching  only  the  pupal  stage  in 
which  the  wing-pads  appear,  and  they  never  leave  the  nest,  but 
pair  within  it,  the  female  laying  fertile  eggs,  though  never  in  such 
numbers  as  a  perfect  queen.  Therefore,  several  of  these  comple- 
mental pairs  may  inhabit  a  colony,  and  there  may  be  no  real 
queen  at  all.  Curiously  enough,  no  queen  of  our  common  species 
has  ever  been  found,  and  we  are  yet  in  ignorance  of  just  where 
the  royal  chamber  is  situated. 


THE    INSECT   WORLD.  67 

Termites  become  injurious  in  one  of  two  ways  :  they  either  eat 
into  wood-work  of  furniture  and  buildings,  or  they  attack  grow- 
ing plants.  In  the  Northern  and  Eastern  United  States  they 
confine  themselves  to  dead  wood,  and  we  have  only  a  single  spe- 
cies,—  Termcs  flavipcs ;  but  in  the  South  and  Southwest  they 
attack  living  plants,  among  them  orange-trees  and  sugar-cane. 
In  buildings  they  sometimes  live  in  beams,  weakening  them  to 
such  an  extent  as  to  threaten  or  actu;illy  cause  collapse.  Not 
many  years  ago  some  of  the  heavy  wooden  supports  of  the  Bos- 
ton State  House  were  found  infested,  and  more  recently  a  build- 
ing in  Cleveland,  Ohio,  was  invaded,  requiring  prompt  measures 
to  prevent  accident.  They  also  attack  stored  products  in  gen- 
eral, skilfully  concealing  their  presence  by  leaving  the  outer  sur- 
face untouched.  Thus,  in  a  pile  of  old  records  stored  in  a  vault  of 
the  United  States  Department  of  Agriculture,  a  large  proportion 
was  found  badly  injured,  though  no  external  trace  appeared.  In 
the  United  States  National  Museum  is  a  mass  of  black  linen 
thread  from  a  South  American  store-house  in  which  the  outer 
form  of  a  pile  of  skeins  is  accurately  preserved,  while  all  below 
is  a  mass  of  hard,  black  galleries.  These  are  made  of  the  partly 
digested  and  excreted  thread  itself ;  and  so  we  find  that  in  the 
galleries  in  logs  or  trees  the  walls  are  composed  of  partly  digested 
wood-fibre. 

Termites  are  often  found  in  decaying  stumps,  and  sometimes 
in  the  roots  and  stems  of  weak  and  dying  plants  ;  in  the  latter 
case  often  hastening  or  inducing  death.  In  the  Southern  States 
they  are  more  abundant  and  troublesome,  attacking  sugar-cane 
and  also  eating  the  bark  of  orange-trees  at  the  crown. 

REMEDIAL    MEASURES. 

Where  the  insects  are  found  in  buildings,  injecting  bisulphide 
of  carbon  into  their  galleries  will  destroy  them.  They  should  be 
traced  to  their  outside  nest,  if  possible,  and,  when  found,  this 
should  be  destroyed.  Frequently  an  old  stump  of  some  large 
tree  may  be  a  centre  from  which  a  district  becomes  infested,  and 
the  bisulphide  should  be  liberally  employed  wherever  the  insects 
are  observed  in  numbers. 

On  growing  plants  the  bisulphide  is  also  useful  in  many  in- 
stances ;  but  here,  too,  the  efitbrt  should  be  made  to  discover  the 


68 


^A'  ECONOMIC  ENTOMOLOGY. 


central  colony,  rather  than  to  protect  individual  trees  or  plants. 
Hot  water  has  been  recommended,  but  is  not  so  effective  as 
the  bisulphide.  Dead  stumps  and  pardy  dead,  infested  plants 
should  be  removed  and  burnt,  to  deprive  the  insects  of  congenial 
quarters. 

The  true  home  of  the  Termites  is  in  the  tropics,  where  they 
are  pests  of  the  first  magnitude.  In  Africa  some  of  the  species 
are  mound-builders,  erecting  turreted  structures  from  ten  to  fif- 
teen feet  in  height,  made  up  of  earth  and  partly  digested  wood 
and  other  fibre. 

Family  psocid^. 

To  this  family  belong  the  minute  "book-lice"  often  found  in 
dusty  corners,  under  loose  paper,  in  collections,  and  in  other  dry 
localities.  They  are  always  small,  resembling  somewhat  a 
"Termite"  in  miniature,  very  active,  running  backward  or  for- 
ward with  equal  facility,  and  furnished  with  very  long,  slender 

antennae  or  feelers.    The  head 


Fig.  36. 


A  book-louse,  X  25  diameters. 


is  very  large,  with  small, 
coarsely  granulated  com- 
pound eyes.  The  mouth  or- 
gans are  mandibulate,  but 
not  at  all  prominent,  and 
fitted  for  gnawing  rather  than 
biting, — whence  the  insects 
have  been  called  Corrodentia 
or  ' '  gnawers. ' '  They  are 
white  or  dirty-yellow  in  color, 
and  look  just  enough  like 
true  lice  to  be  mistaken  for 
them  under  some  circum- 
stances. Occasionally  con- 
ditions favor  their  increase  in 
houses,  and  almost  in  a  day 
it  will  be  overrun,  beds  and 


bedding  being  especially  favored,  to  the  horror  of  the  housewife, 
who  almost  invariably  mistakes  their  true  character.  Several 
times  within  my  experience  I  have  received  these  creatures  with 
anxious  entreaties  for  a  remedy,  and  equally  anxious  requests  for 
secrecy.     The  Psocids  may  be  always  distinguished  from  para- 


THE    INSECT    WORLD.  69 

sites  by  -their  very  rapid  motions  and  their  long  antennae  or 
feelers.  Their  food  is  starch,  where  they  can  get  it,  or  dry  ani- 
mal or  vegetable  matters,  and  they  can  be  driven  out  by  a  free 
use  of  naphthaline  crystals.  Their  injury  in  libraries  is  done  by 
eating  the  starched  surface  of  bindings,  plates,  and  pages,  and 
so  disfiguring  them. 

The  forms  just  described  are  all  wingless  throughout  their  en- 
tire life,  Atropos  [^Clothilla)  divinatoria  and  A.  pulsatoria  being 
common  species.  In  some  mysterious  way  the  term  "death- 
watch"  has  been  applied  to  these  creatures,  and  they  have  been 
credited  with  making  the  ticking  sound  often  heard  at  night  in 
old  houses,  and  which  is  supposed  to  give  warning  of  a  death  to 
come. 

But  there  are  some  winged  forms,  and  these  somewhat  resem- 


FiG.  37. 


Psociis  lineatus,  much  enlarged. 

ble  overgrown  plant  lice,  differing,  of  course,  by  the  mandibulate 
mouth.  These  winged  Psocids  sometimes  occur  in  great  num- 
bers on  the  bark  of  trees,  in  my  experience  most  often  on  cherry 
and  orange,  where  they  feed  upon  lichens  and  other  dry  vege- 
table matter.  They  sometimes  create  alarm  when  great  numbers 
are  noticed  by  the  farmer  ;  but  none  of  them  are  in  the  least  in- 
jurious. They  are  more  cylindrical  in  appearance  than  the  wing- 
less forms,  and  the  thoracic  parts  are  better  developed  and  larger 
than  the  head,  which  bears  the  same  coarsely  granulated  eyes 
and  long  antennae.  When  a  group  of  specimens  is  disturbed 
they  run  in  every  direction,  and  often  drop  to  the  ground 
rather  than  use  their  wings  in  flight.     Altogether,  this  family 


70 


AN  ECONOMIC  ENTOMOLOGY. 


contains  insects  that  simulate  injurious  forms,  while  doing  little 
or  no  actual  damage  themselves. 

Family  mallophagid^. 

The  literal  meaning  of  this  term  is  "wool  eater,"  and  it  ap- 
propriately expresses  the  habits  of  some  of  the  species.  All 
members  of  this  family  are  parasitic,  and  are  known  as  biting 
lice  ;  never  sucking  blood,  but  feeding  upon  young  hair,  feathers, 
skin-scales,  clots  of  blood,  and  scabby  or  other  scurfy  material 
found  on  the  skin  or  among  hair  and  feathers.  They  infest 
warm-blooded  animals  only,  and  principally  birds,  whence  the 
term  "bird-lice"  has  been  erroneously  applied  to  the  entire 
group.     All  the  common  farm  animals  except  the  pig  are  infested 

Fig.  38. 


Biting-lice.— (I,   clog-louse,    Trichodectus  latus ;  b,   sheep-louse,    Trichodectiis  sphcero- 
cephaliis  ;  <-,  turkey-louse,  Goniodes  siylifer. 

by  some  species  of  this  family,  and  all  the  poultry  or  fowls  are 
troubled  to  a  greater  or  less  extent. 

The  insects  are  all  small,  flattened,  with  large,  prominent  head, 
often  bulging  eyes,  and  short  antennae  or  feelers.  The  legs  are 
short  and  stout,  fitted  for  holding  to  and  moving  among  hair  or 
feathers,  and  the  abdomen  is  oval.  No  trace  of  wings  is  ever 
developed. 

The  eggs  are  fastened  to  the  hair  or  feathers  of  the  host,  and 
in  a  few  days  the  young  emerge,  not  differing  from  their  parents 
except  in  size  and  sexual  immaturity.     The  entire  life  is  thus 


tup:  insect  world.  71 

passed  on  the  host,  and  the  insects  usually  spread  from  one 
animal  to  tlic  other  on  occasions  of  contact,  or  through  litter 
into  which  some  specimens  may  crawl  or  be  thrown.  They  also 
crawl  upon  the  wood-work  of  coops  and  stables,  and  thence  upon 
such  animals  as  may  rest  against  it. 

The  only  way  to  reach  these  insects  is  by  means  of  poisons 
acting  through  the  respiratory  system,  and  this  is  not  difficult, 
because  the  spiracles  are  not  well  protected.  Barn-yard  fowls 
will  keep  themselves  tolerably  free  if  furnished  with  plenty  of  fine 
dust.  The  finer  it  is  the  more  effective,  and  the  birds  will  so 
thoroughly  powder  themselves  that  few  of  the  parasites  can 
escape.  Cleanliness  on  the  roosts  and  in  hen-houses  is  impera- 
tive, and  a  liberal  use  of  whitewash  and  occasionally  of  kerosene 
on  all  the  wood-work  is  useful.  A  badly  infected  house  may  be 
cleaned  by  shutting  it  up  tight  for  twenty-four  hours,  and  evap- 
orating in  a  shallow  dish  a  few  ounces  of  bisulphide  of  carbon. 
This  kills  all,  save  eggs,  and  the  treatment  should,  therefore,  be 
renewed  a  week  later  to  reach  such  as  may  have  hatched  since 
that  previously  made.  It  has  also  been  recommended  to  hang 
small  open  vials  of  bisulphide  below  the  perches,  and  this,  it  is 
asserted,  kills  the  parasites  without  discommoding  the  fowls. 

On  farm  animals  greasy  mixtures  may  be  successfully  employed, 
or  carbolic  or  tobacco  washes  or  dips.  For  larger  animals — 
horses,  cows,  or  mules — a  thorough  grooming  with  comb  and 
brush,  dipping  the  brush  into  a  kerosene  emulsion  diluted  five 
times  so  as  to  moisten  all  parts  of  the  body,  is  decidedly  the  best 
method.  This  must  be  duplicated  a  week  later  to  reach  any  that 
may  have  hatched  from  eggs  since  the  previous  treatment.  On 
large  herds,  badly  infested,  the  kerosene  emulsion,  diluted  nine 
times,  is  simply  sprayed  on  the  animals  as  they  pass  through  a 
narrow  opening,  the  application  renewed  at  intervals  of  a  week, 
until  no  more  lice  appear. 

With  so  considerable  a  range  of  remedial  and  preventive 
measures  no  serious  trouble  from  these  parasites  need  be  appre- 
hended, and  it  remains  only  to  urge  again  the  utmost  cleanliness 
everywhere  as  the  best  of  all  preventive  measures. 

All  the  neuropterous  orders  heretofore  treated  have  had  the 
metamorphosis  incomplete,  and  are  therefore  classed  as  pseudo- 


72 


AN  ECONOMIC  ENTOMOLOGY. 


or  false-neuroptera.  While  they  are  not  directly  followed  in  the 
classification  by  the  true  neuropterous  series,  yet  for  convenience 
they  may  be  so  arranged  here,  and  not  entirely  without  reason, 
because  they  are  descendants  of  the  same  stock. 

Order  NEUROPTERA. 

As  this  term  is  now  limited  it  includes  only  those  nerve- 
or  net-winged  forms  with  complete  metamorphosis  in  which 
the  biting  mouth  parts  are  well  developed  and  not  prolonged. 
The  thoracic  parts  are  large,  frequently  the  prothorax  is  dis- 
tinctly separated  and  square,  and  the  entire  insect  is  somewhat 
flattened. 

Of  this  type  are  the  large  forms  like  Corydalns  and  Chaicliodes, 
and  the  peculiar  Raphidia  found  on  the  western  coast,  members 
of  the  family  Sialidce.  The  head  is  large  and  broad,  the  mandi- 
bles well  or,  as  in  the  male  Corydalus,  even  enormously  developed, 
the  antennae  long  and  many  jointed  ;  in  Chauliodes  pectinated. 
The  prothorax  is  always  distinct,  square  or  oblong,  in  Raphidia 
very  long  and  narrow,  the  other  thoracic  segments  well  developed 
and  loosely  held  together.  The  abdomen  is  soft  in  texture,  and 
as  a  whole  the  forms  appear  loosely  jointed.  The  broad  wings 
lie  nearly  flat  on  the  back  and  much  exceed  the  tip  of  the  ab- 
domen, the  hind  pair  being  partially  folded  at  rest.  The  eggs 
of  Corydalns  are  laid  in  masses  on  leaves  or  sticks,  coated  with  a 
water-proof  secretion,  and  from  them  hatch  flattened  six-footed 
larvae,  which  live  under  stones  or  other  shelter  on  the  bottom  of 
running  streams.  They  are  furnished  with  gill  tufts,  through 
which  they  obtain  oxygen,  and  prey  on  whatever  insects  or  larvae 
may  come  within  their  reach.  In  turn  they  are  preyed  upon  by 
fishes,  and  the  larvae  of  the  Corydalns  cornntns,  or  "dobson," 
make  excellent  bait,  being  locally  known  as  "  hellgrammites." 
When  full-grown  they  come  to  the  edge  of  the  stream  and,  under 
stones  or  other  shelter,  change  to  quiescent  pupae,  in  which  all 
of  the  limbs  are  free  and  the  form  of  the  future  adult  is  fully 
shown. 

The  species  of  this  family  are  interesting,  but  of  no  sort  of 
economic  importance. 

Not  so  the  next  family,  the  Hemerobiidcs ,w\\\ch.  contains  numer- 
ous species  of  interest,  all  of  them  predaceous  and  beneficial  to 


THE    IXSECT   WORLD. 
•       Fig.  39. 


73 


The  "  hellgrammite"  or  "  dobson"  in  all  its  stages. — Upper  series  :  a,  the  larva  ;  b,  the 
pupa  ;  c,  the  male  adult  ;  (/,  the  head  of  the  female  :  in  the  lower  series  the  leaf  bears 
egg  masses  at  aa,  enlarged  at  be ;  d,  the  larva  just  hatched,  with  details  from  e  toj. 


74 


AN  ECONOMIC  ENTOMOLOGY. 


the  farmer.  There  are  several  sub-famUie.s,  which  together  are 
termed  "lace-winged  flies,"  from  their  delicate,  finely-reticulated 
or  netted  wings,  which  lie  flat  and  are  not  folded.  The  insects 
are  slight,  and  in  the  species  allied  to  Hcmerobiiis  the  colors  are 
brownish  or  smoky.  They  are  less  common  than  the  forms 
allied  to  Chrysopa^  which  are  green,  with  long  antennae  and 
prominent,  bright,  yellowish-brown  eyes,  which  have  given  them 
the  name  "golden-eyed  flies"  in  some  localities.  They  are 
commonly  found  in  fields  or  along  the  edges  of  woods,  and  emit, 
when  handled,  a  peculiarly  sickening  odor  which  is  quite  unmis- 
takable when  once  known.  In  the  adult  stage  the  insects  feed 
little  or  not  at  all ;  but  the  larvae,  known  as  "  aphis  lions,"  feed 
almost  constantly,  their  prey  being  small,  soft-bodied  insects  of 
all  kinds,  aphids  or  plant-lice  ranking  as  special  favorites. 


Fig.  40. 


A  lace-wiiiged  Hy,  Ckrysopa  oculata. — a,  the  ejfgs  ;  b,  the  larva ;  d,  same,  feeding  on  a 
pear-psylla  ;  e,  cocoon,  from  which  /,  the  adult,  has  escaped  ;  g,  head  of  adult  in  front, 
enlarged. 

The  entire  life  history  of  the  insects  is  interesting.  The  female 
in  ovipositing  touches  the  end  of  the  abdomen  to  the  surface, — 
usually  a  leaf, — upon  which  the  eggs  are  to  be  laid,  and  then 
elevates  her  body  about  a  quarter  of  an  inch,  emitting  at  the 
same  time  a  viscid  thread  which  hardens  on  exposure  to  the  air. 
At  the  tip  of  this  the  q%%  is  fastened,  and  we  get  thus  a  little 


THE    INSECT    WORLD. 


75 


grove  ol  eggs  on  stilts.  This  is  supposed  to  insure  their  safety 
from  wandering  predaceous  forms  that  might  otherwise  feed  upon 
them.  Wlien  the  larva  hatches  it  climbs  down  the  slender 
thread,  and  attacks  and  feeils  upon  the  hrst  suitable  specimen  it 
can  find, — usually  a  young  plant-louse.  Now,  here  is  another 
peculiarity  :  it  does  not  chew  or  tear  its  prey,  but  holds  it  firmly, 
sucking  the  juices  by  means  of  grooves  on  the  inner  side  of  the 
large  mandibles,  which  are  closed  by  the  slender  maxillae.  The 
larva  grows  rapidly,  becoming  rather  more  than  a  quarter  of  an 
inch  in  length,  narrow,  spindle-shaped,  pointed  at  the  anal  ex- 
tremity, the  head  distinct  and  with  prominent  sickle-shaped 
mandibles.  When  full-grown  it  spins,  by  means  of  anal  glands, 
a  perfectly  spherical,  white,  silken  cocoon  of  very  dense  texture, 
and  small  in  proportion  to  the  lar\a.  It  resembles  a  moderate 
sized  pearl  in  form  and  appearance,  and  when  the  adult  is  ready 
to  emerge,  a  circular  lid  is  lifted  off  to  give  the  matured  pupa 
exit.  Comparing  the  fully  developed  insect  with  the  cocoon 
from  which  it  issued,  the  marvel  is  great  that  it  was  ever  packed 
away  in  so  small  a  space. 

These  insects  are  really  of  much  practical  value,  frequenting, 
as  many  of  them  do,  tilled  fields  and  orchards,  feeding  upon 
larvae,  plant-lice,  and  similar  creatures.  They  become  injurious, 
however,  in  some  parts  of  California,  where  they  attack  and 
destroy  coccinellid  or  lady-bird  larvae. 

Somewhat  closely  allied  in  all  stages  to  the  Hemerobiidcz  are 
the  Myy-melconidcE^  or  "ant-lions,"  but  they  are  larger,  with 
longer  and  narrower  wings,  and  clubbed  antennae.  As  before, 
the  adults  are  graceful,  harmless  creatures,  which  fly  mostly  at 
night,  while  the  larvae  are  predatory,  resembling  the  "aphis- 
lions"  in  structure,  save  that  they  are  broader  and  chunkier  in 
appearance.  They  are  also  peculiar  in  that  many  of  them 
capture  their  prey  in  pits  or  traps. 

In  constructing  its  trap,  the  larva  usually  selects  a  spot  of  mod- 
erately compact,  fine  sand,  and  excavates  a  funnel-shaped  pit 
with  the  sides  as  steep  as  the  sand  will  lie.  It  remains  buried 
and  invisible  in  a  little  gallery  at  one  side  of  the  bottom,  in  wait 
for  any  unlucky  creature  that  may  come  within  reach.  Ants  are 
the  most  frequent  victims,  from  their  wandering  habits  and  their 
tendency  to  investigate,  a  pause  at  the  brink  resulting  in  a  slip  of 


76 


AN  ECONOMIC  ENTOMOLOGY. 


sand  and  a  tumble  into  the  jaws  of  the  enemy.     Should  the  ant 
recover  a  footing  before  reaching  the  bottom,  a  shower  of  sand, 

sent  by  the  vigilant 
Fig.  41.  1  u  1 

larva  below,  over- 
whelms and  brings 
it  down  to  its  death. 
When  the  juices 
are  exhausted,  the 
empty  shell  is 
thrown  out  and  the 
pit  is  repaired  for 
other  victims. 
Sometimes  pits  are 
made  in  saw-dust 
or  friable  leaf  mold 
and  some  make  no 
pits  at  all. 

The  adults  are 
of  two  rather  dis- 
tinct series  :  the 
first  with  short 
antennae  which 
thicken  rather  gradually  toward  the  tip,  including  Myrmeleo  ;  the 
second  with  long,  slender  antennae,  enlarging  suddenly  into  a 
flattened  club.  The  head  is  larger  and  the  body  more  robust, 
covered  with  stiff  bristly  hair,  giving  the  insects  a  fierce  appear- 
ance. The  most  common  genus  is  Asca/aphus,  and  the  larval 
habits  are  not  known,  though  it  is  probable,  from  what  we  learn 
of  foreign  species,  that  they  do  not  build  pits  or  traps.  Though 
interesting,  the  family  is  of  no  economic  importance. 

An  odd  family  is  the  Mantispidtr,  so  named  from  the  peculiar 
resemblance  which  they  bear  to  the  Orthopterous  genus  Mantis. 
The  species  are  not  common,  and  are  easily  recognized  by  the 
enormously  developed  forelegs,  which  are  fitted  for  grasping,  and 
are  inserted  into  a  long  and  slender  prothorax.  They  are  pre- 
daceous,  while  their  larvae  are  parasitic  in  the  egg-sacs  of  spiders. 
The  eggs  are  laid  on  stalks,  as  with  the  "lace-wings,"  and  the 
slender  larvae  that  hatch  from  them  live  through  the  winter  with- 
out food,  becoming  active  again  in  spring,  when  they  seek  the 


Myrmeleo  species. — The  adult  above;  the  larva  in  its  pit, 
which  is  shown  in  section. 


THE    INSECT    llOKLD. 


77 


egg-sacs  of  Lycosid  or  running  spiders.  The  larva,  that  succeeds, 
enters  the  sac  and  begins  feeding  upon  the  eggs,  gradually  losing 
its  active  form  and  becoming  clumsy  and  grub-like.  The  pupa 
forms  within  the  larval  skin,  and  after  midsummer  the  adult 
appears. 

Very  curious  creatures  are  the  Panorpidcc,  or  ' '  scorpion- 
flies,"  usually  ranked  as  an  order  under  the  term  Mccoptera. 
They  have  netted  wings  similar  to  but  more  robust  than  the 
"  lace-wings,"  but  have  the  mouth  prolonged  into  a  beak,  at  the 
end  of  which  the  biting  parts  are  situated.  In  the  genus  Pmi- 
orpa  the  males  have  a  pair  of  huge  anal  forceps,  curved  up  some- 


FiG.  43. 


Manlisf'a  species. — Showing  the 
legs  and  body  from  the  side. 


A  Panorpa,  or  scorpion-fly,  and  its  larva. 


what  like  the  sting  of  a  scorpion,  and  from  this  the  common  name 
is  derived.  As  a  matter  of  fact,  the  insects  are  entirely  harmless 
save  to  others  of  their  kind,  for  they  are  predaceous.  The  genus 
Bittacus  is  narrower  winged,  with  unusually  long  legs,  looking 
somewhat  like  a  crane-fly  at  first  sight.  Species  belonging  to  the 
genus  Boreus  occur  on  the  snow  in  very  early  spring.  The  larvae, 
so  far  as  we  know  them,  are  predaceous  and  resemble  caterpillars 
in  appearance  ;  they  have  eight  pairs  of  fleshy  prolegs,  however, 
while  no  true  caterpillar  ever  has  more  than  five.  None  of  the 
species  are  common  and  none  are  of  practical  importance  to  the 
farmer. 

The  "  caddice-flies"  have  also  been  elevated  to  ordinal  rank 
under  the  name  Trichoptera,  or  "hairy-winged."  The  adults 
have  moderately  developed  bodies,  with  large  wings,  which  are 
more  or  less  densely  clothed  with  hair,  the  first  pair  often  thicker 


78 


AN   ECONOMIC  ENTOAIOLOGY. 


than  the  second,  which  are  folded  beneath  them.  Both  wings 
have  numerous  longitudinal  veins  connected  by  only  a  few  cross- 
veins,  losing  the  reticulated  appearance  of  the  more  typical  Neu- 
roptera,  and  resembling  more  closely  some  of  the  lower  moths, 
for  which,  indeed,  some  of  the  smaller  forms  may  be  easily  mis- 
taken. The  mouth  parts,  however,  though  rudimentary,  are 
mandibulate  in  type,  and  there  is  no  approach  to  the  coiled 
tongue  of  the  Lepidoptera.  The  antennae  are  very  long  and 
slender,  resembling  hairs  rather  than  jointed  organs. 

The  species  are  found  frequently  in  great  numbers  along  the 
banks  of  streams,  ponds,  or  ditches,  in  which  the  larval  life  is 
passed.  The  larvae  are  caterpillar-like,  with  three  pairs  of  unusu- 
ally well-developed  legs,  and  live  in  cases  which  they  make  of 
bits  of  sticks,  moss,  leaves,  stones,  shells,  or  other  material,  held 
together  by  silken  threads  with  which  the  entire  inside  of  the 
habitation  is  lined.  Frequently  the  cases  are  roughly  and  irreg- 
ularly constructed  ;  but  as  often  they  are  marvels  of  skilled  work- 
manship. Small 
Fig.  44.  stones  are  fitted  so 

carefully  that  no 
break  as  large  as 
a  needle-point  oc- 
curs, and  some- 
times they  mimic 
shells  so  closely 
that  conchologists 
have  been  deceived 
into  believing  them 
such.  In  these 
cases  the  larvae  live, 
and  from  them  they 
obtain  their  com- 
mon name  "  caddice  "  or  case-flies.  Whatever  the  form  of  the 
case,  the  insect  lives  in  and  carries  it  about  everywhere  through- 
out the  larval  life,  crawling  about  under  water  by  means  of  the 
large  legs  and  keeping  the  soft,  white,  hind  body  constantly  pro- 
tected. Some  live  in  ponds  or  sluggish  streams,  others  in  rapid 
brooks  and  torrents  ;  some  are  vegetarians,  some  are  predatory, 
feeding  on  other  larvae  or  even  on  small  fish.     Some  forms  con- 


A  caddice-fly,  Limnophilus  rkombicus,  its  larva,  and  at  a 
the  larval  case. 


THE    INSECT   WORLD.  79 

Struct  effective  nets  in  which  very  young  fish  become  entangled 
and  fall  easy  victims  to  the  insect  fishermen.  Streams  in  which 
these  kinds  of  caddice-flies  are  abundant  are  not  easily  stocked 
with  fish  unless  the  fry  is  so  well  grown  as  to  be  out  of  danger 
from  this  source.  Practically,  the  insects  are  of  no  importance 
to  the  agriculturist. 


CHAPTER    IV. 

THE    ORTHOPTERA. 

Grasshoppers,  Crickets,  Katydids,  etc. 

The  order  Orthoptera,  or  ' '  straight-winged' '  insects,  includes 
those  forms  with  biting  mouth  parts  and  an  incomplete  meta- 
morphosis, commonly  known  as  "earwigs,"  "grasshoppers," 
"locusts,"  "crickets,"  and  "roaches." 

The  distinctive  characters,  aside  from  those  just  mentioned, 
are  that  the  fore-wings  are  firmer  in  texture  than  the  secondaries, 
and  that  the  latter  are  folded  fan-like,  or  plaited,  when  at  rest. 
They  are  then  covered  by  the  primaries,  which  are  usually  nar- 
row and  of  little  use  in  flight,  resembling  in  this  respect  the  wing- 
covers  of  the  beetles,  and  here  termed  "tegmina."  With  few 
unimportant  exceptions  the  insects  belonging  to  this  order  are 
herbivorous,  and  among  them  are  some  of  the  most  destructive 
pests  to  agriculture,  such  as  the  migratory  locusts  or  grasshop- 
pers, which  have  been  known  and  dreaded  since  the  dawn  of 
history,  and  the  "Rocky  Mountain  locust,"  of  evil  repute  in 
our  own  country. 

First  come  the  Forficiilidce ,  or  ear-wigs,  generally  accepted 
as  forming  a  separate  order  under  the  name  Dermaptera  (skin- 
wing)  or  Euplexoptera  (well-folded  wing).  They  differ  from  all 
the  other  Orthoptera  by  having  a  pair  of  anal  forceps  and  by 
their  resemblance  to  the  Staphylinidce,  a  family  of  half-winged 
beetles.  The  wing-covers  are  short  and  thick,  not  extending  to 
the  middle  of  the  flattened  abdomen,  and  the  large  hind  wings 
are  first  plaited  fan-like  around  a  point  near  the  middle  of  the 
anterior  margin,  and  are  then  transversely  folded  into  a  neat  little 


8o 


AN   ECONOMIC   ENTOMOLOGY. 


packet,  which  is  tucked  away  under  the  fore-wings  by  means  of 
the  anal  forceps.  Some  of  the  species,  however,  lack  the  wings 
entirely,  in  which  case  the  peculiar  anal  forceps  and  the  beetle- 
like form  distinguish  them  quite  readily. 


Fig.  45. 


Cases  or  caddices,  made  by  the  larvae  of  Trichoptera,  illustrating  differences  of  shape 
as  well  as  varieties  of  material  used. 


Except  in  the  South,  ear-wigs  are  rare  in  the  United  States, 
and  not  injurious.  In  parts  of  Europe  and  in  sub-tropical  and 
tropical  countries  they  are  sometimes  abundant  and  frequently 
annoying,  eating  at  night  into  flowers  in  which  they  hide  during 
the  day.  In  vine-  and  flower-covered  houses  or  arbors  they  are 
sometimes  a  nuisance,  and  their  long,  slender  form  and  nocturnal 
habits  have  given  rise  to  the  unfounded  belief  that  they  crawl 
into  the  ears  of  sleepers  and  kill  them.  The  female  lays  a  small 
number  of  eggs  only,  and  broods  over  or  watches  them  until 
some  little  time  after  they  are  hatched. 

The  more  typical  Orthoptera  may  be  conveniently  divided 
into  series  by  their  leg  structure  and  method  of  locomotion,  as 
follows  : 


THE    INSECT   WORLD. 


8i 


1.  The  Cursoria,  or  "'runners,"  with  stout,  long  legs  fitted 
for  rapid  motion, — like  the  roaches. 

2.  The  Raptoria,  or  "graspers,"  in  which  the  forelegs  are 
developed  into  grasping  organs  and  the  insects  are  predaceous, 
— in  strong  contrast  to  all  the  others  of  the  order. 

3.  The  Ambidatoria,  or  "walkers,"  in  which  the  legs  are 
long  and  slender,  useful  for  deliberate  progress  only. 

4.  The  Saltatoria,  or  "jumpers,"  which  have  the  hind  legs 
unusually  long  and  well  developed,  fitted  for  leaping, — like  grass- 
hoppers and  crickets. 

KiG.  46. 


Ear-wig.— I,  mature  male  ;  2,  nymph  ;  3,  the  wing,  showing  the  radiate  type  of  pleating. 

The  Oirsoria,  or  "runners,"  belong  to  the  family  Blattida, 
or  roaches.  They  are  flattened,  rather  soft,  repulsive  creatures, 
with  long,  powerful,  spiny  legs  ;  long,  slender,  filiform  antennae, 
and  the  head  bent  under  the  body  so  as  to  locate  the  mouth 
parts  between  the  front  legs.  They  are  brown  or  yellow  in  color, 
are  nocturnal  in  habit,  and  live  under  bark  or  in  crevices,  for 
which  their  flattened  form  suits  them  peculiarly  well. 

Roaches  eat  almost  anything,  or  are  practically  omnivorous. 
They  are  among  the  most  ancient  type  of  insects,  and  are  yet 
disgustingly  common  in  the  tropics,  their  numbers  decreasing 
northwardly  until  only  a  few  cosmopolitan  forms  are  found  do- 
mesticated in  houses. 

A  peculiar  feature  in  the  life  history  is  the  method  of  oviposi- 
tion.  The  eggs  mature  at  about  the  same  time,  and  are  closely 
packed  into  a  somewhat  bean-shaped  case,  which  the  female  car- 
ries about  with  her,  partially  protruding  from  the  end  of  the  ab- 
domen, for  several  days.      It  is  then  deposited  intact  in  some 

6 


82 


AN  ECONOMIC   ENTOMOLOGY. 


Fig.  47. 


convenient  crevice,  and  very  soon  thereafter  the  young  issue. 
Modifications  of  this  habit  occur,  and  in  some  cases  the  eggs  act- 
ually hatch  within  the  body  of  the  mother, 
who  thus  becomes  viviparous. 

I  am  not  aware  that  roaches  ever  become 
injurious  to  growing  crops  in  our  country  ; 
but  two  species  are  certainly  great  nuisances 
in  houses, — the  "  Croton  bug,"  Phyllo- 
dromia  germanica,  and  the  ' '  black  beetle, ' ' 
Periplaneta  orientalis.  Both  are  introduced 
and  almost  cosmopolitan  forms.  The  former 
is  small,  averaging  about  half  an  inch  in 
length,  and  is  winged  in  both  sexes.  The 
latter  is  larger,  varying  between  three- 
fourths  and  one  and  one-fourth  inches,  with 
short  wings  in  the  male  and  mere  rudiments 
in  the  female. 

The  most  satisfactory  way  of  dealing  with  these  insects  is  by 
means  of  a  phosphorus  paste,  spread  upon  bits  of  soft  bread 
and  placed  near  their  haunts,  all  other  food  particles  being  care- 
fully put  out  of  reach.  A  short  period  of  such  treatment  will 
usually  prove  effective.     Almost  as  good  is  a  mixture  of  equal 

Fig.  48. 


Forjicula  tcsniata, 
and  female. 


male 


The  Croton  bug,  Phyllodromia  geynnanica. — a,  first  stage;  b,  second  stage;  c,  third 
stage ;  rf,  fourth  stage  ;  e,  adult ;  f,  adult  female  with  egg-case  ;  g,  egg-case,  enlarged  ; 
h,  adult  with  wings  spread.    All  natural  size  except^. 


parts  of  finely  powdered  chocolate  and  borax,  dusted  into  the 
crevices  where  the  insects  hide.  The  mixture  should  be  inti- 
mate, and  is  best  made  in  a  mortar,  so  that  with  each  part  of 


THE    INSECT   JVORLD.  83 

chocolate,  of  which  the  roaches  are  very  fond,  they  will  get  also 
a  particle  of  borax,  which  is  poisonous  to  them.  This  mixture 
has  proved  successful  in  many  instances  within  my  own  experi- 
ence, and  has  the  advantage  of  being  cheap  as  well  as  non-poi- 
sonous to  man. 

The  Raptor ia,  or  "graspers,"  form  one  family,  the  Mantidcs, 
as  odd  in  appearance  as  their  habits  are  unusual.  They  are 
clumsy,  heavy-bodied  insects,  with  short,  broad  wings,  the 
middle  and  hind-legs  rather  weak,  but  with  an  unusually  long 
and  slender  prothorax,  to  which  is  attached  a  pair  of  huge 
forelegs,  armed  with  sharp  spurs  and  spines.  The  head  is  usu- 
ally much  broader  than  the  prothorax,  with  prominent,  often 
globular  eyes,  short  antennae,  and  so  set  as  to  be  capable  of  lat- 
eral motion.  It  is,  in  fact,  the  only  type  capable  of  turning  its 
head  ! 

The  insects  are,  as  a  rule,  sluggish,  those  occurring  with  us 
incapable  of  rapid  motion,  depending  entirely  upon  such  prey  as 

Fig.  49. 


The  Oriental  roach,  Periplaneta  oricntalis. — a,  the  male;  b,  the  female;  r,  egg-case. 

comes  within  easy  reach,  and  securing  this  through  their  often 
remarkable  resemblance  to  the  vegetation  among  which  they 
lurk.  In  other  countries  there  are  some  more  active  species, 
capable  of  pursuing  and  capturing  their  prey.  Their  colors  are 
green  or  yellowish,  like  leaves,  or  brownish,  like  bark  ;  the  wing- 
covers  sometimes  mottled  and  roughened  to  mimic  an  irregu- 
larity or  o\ergrown  injury  on  a  trunk   or  branch.     Thus  con- 


84 


AN  ECONOMIC   ENTOMOLOGY. 


cealed,  they  rest,  body  close  to  the  surface,  prothorax  elevated, 
and  forelegs  held  in  the  attitude  of  prayer,  whence  the  term 
"praying  mantes,"  Mantis  religiosa,  which  is  applied  to  a  for- 


FiG.  50. 


Stagmomantis  Carolina.— a,  the  female  ;  b,  tlie  male. 


eign  species.  But  prayer  is  far  from  the  object  in  view,  as  any 
small  insect  that  happens  within  reach  learns  to  its  cost.  A  sud- 
den clasp  wounds  and  crushes  it  into  helplessness,  and  the  Mantis 
then  leisurely  devours  its  victim,  the  forelegs  serving  admirably 
as  hands  in  the  operation. 

The  eggs  are  laid  in  a  mass  on  twigs  or  branches,  held  to- 
gether by  a  peculiar  silken  fibre  which  encases  and  protects  each 
^%^  as  well  as  the  entire  cluster. 

The  predaceous  habit  excludes  these  insects  from  the  category 
of  injurious  forms  ;  but  they  are  not  sufficiently  common  in  our 
country  to  be  of  any  practical  advantage.  They  are  southern  in 
geographical  range,  and  only  one  species,  Stagmomantis  Caro- 
lina, is  rarely  found  north  of  New  Jersey  on  the  Atlantic  coast. 

The  Ambulatoria,  or  "walkers,"  include  a  series  of  very 
curious  species,  popularly  known  as  "walking-sticks"  and 
"walking-leaves,"  represented  in  our  fauna  by  a  few  species 
belonging  to  the  family  Phas^uidcs.     The  true  home  of  these 


THE    INSECT    WORLD. 


85 


Fig. 


forms  is  in  the  tropics,  where  we  find  excellent  examples  of  pro- 
tective mimicry  in  the  development  of  wings  so  colored  and 
veined  that  the  insects  cannot  be  easily  distinguished  from  the 
foliage  upon  which  they  feed.  Our  own  species  have  mere  rudi- 
ments of  wings  only  ;  but  have  very  long,  slender  bodies,  an- 
tennae, and  legs.  When  at  rest,  with  long  legs  fully  stretched 
out,  the  resemblance  to  a  bare  twig  or  a  torn  leaf  is  perfect. 

The  insects  move  slowly  and  awkwardly,  feeding  on  the  foliage 
of  a  variety  of  forest  trees,  and  are  occasionally  quite  destructive. 
They  do  not  extend  north  of  the  Middle  States 
on  the  Atlantic  Coast,  but  occur  everywhere  in 
the  Central  and  Southern  States,  reaching 
northwardly  in  the  Mississippi  Valley  much 
further  than  in  the  East.  So  far  as  I  am  aware, 
they  never  attack  field  or  orchard  crops,  and 
are  not  strictly  injurious  to  agriculture,  though 
they  may  be  to  forestry.  Unlike  the  families 
previously  mentioned,  they  take  no  care  of  their 
eggs,  but  the  females  drop  them  at  random  upon 
the  ground.  It  has  been  said  that  in  a  badly- 
infested  piece  of  woodland  the  pattering  of  the 
eggs  as  they  fall  from  the  trees  sounds  like  rain. 

Thoroughly  and  carefully  burning  over  in- 
fested woodland  during  some  favorable  period 
in  winter  will  prove  effective  in  case  remedial 
measures  become  necessary  ;  spraying  with 
arsenites  can  be  resorted  to  for  the  protection 
of  single  or  small  groups  of  trees. 

In  the  Saltatoria,  or  "junipers,"  we  find  the 
most  destructive  species,  and  they  separate 
readily  into  three  families  :  the  Acridiidce,  or 
"short-horned  grasshoppers  ;"  the  Locustidce, 
or  "long-horned  grasshoppers"  and  "katy- 
dids ;"  and  the  GryllidiB,  or  "  crickets,"  which 
have  long  horns  or  antennae  like  the  Locustidce, 
but  cylindrical  instead  of  flat,  sword-like  ovipositors. 

The  Acridiidce,  or  short-horned  grasshoppers,  are  among  the 
most  common  and  best  known  of  our  insects,  flying  up  or  jump- 
ing out  of  the  way,  however  one  turns,  among  grass  or  low  herb- 


Egg  masses  ol 
Stagmoniantis  Car- 
olina, from  above 
and  from  side. 


86 


ajv  economic  entomology. 


Fig.  52. 


Walking-sticks,  Diapheromerafenwrata. — a  and  b,  the  eggs,  enlarged,  from  the  eage 
and  side;  c,  young  just  hatching  ;  d,  the  male,  and  e  the  female  adult. 


THE    INSECT   WORLD. 


87 


age  in  roads,  fields,  or  meadows,  but  not  favoring  dark  woods. 
Tiiey  have  no  external  ovipositor,  but  the  female  is  furnished 
with  four  horny  valves,  between  which  the  eggs  pass,  and  which 
are  also  useful  in  making  the  hole,  in  soil  or  wood,  into  which  the 
eggs  are  laid.  The  term  "short-horned,"  as  applied  to  these 
insects,  is  relative,  and  means  that  the  antenna;  are  moderately 
stout,  the  joints  well  marked,  and  the  whole  member  not  as  long 
as  the  entire  insect, — in  fact,  rarely  even  half  as  long.     A  curious 


Fig.  53. 


Rocky  Mountain  locust  ovipositing. — a,  a,  females  with  abdomen  inserted  in  the  soil ; 
b,  an  egg-pod  broken  open  and  lying  on  the  surface  ;  c,  a  few  scattered  eggs  ;  d,  section 
of  soil  removed  to  show  eggs  being  put  in  place  ;  e,  an  egg-pod  completed  ;  /,  an  egg- 
pod  sealed  over. 

character  is  a  pair  of  ears  situated  one  on  each  side  of  the  basal 
segment  of  the  abdomen,  and  we  therefore  expect  and  do  find 
that  most  of  the  species  are  capable  of  making  some  kind  of 
song  or  noise,  though  this  ability  is  confined  to  the  male. 

A  series  of  species  characterized  by  a  very  receding  front, 
meeting  the  vertex  of  the  head  in  an  acute  angle,  is  referred  to 
the  sub-family  TryxalincB,  of  which  there  are  many  species 
throughout  our  country,  none  of  them  abundant  enough  to  be 
injurious.  They  are  partial  to  low,  sedgy  land  or  meadows,  es- 
pecially on  sandy  soil,  and  I  have  met  with  the  species  most 
abundantly  near  the  sea,  or  on  the  sandy  plains  not  far  inland. 
Some  species  are  common  on  or  near  cranberry  bogs,  but  are  not 
injurious. 

Quite  a  series  of  species  is  referred  to  the  sub-family  CEdipodin(e, 


88 


AN  ECONOMIC  ENTOMOLOGY. 


Chortophaga  viridifascia — a,  larva  ;  b,  adult. 


and  these  differ  from  the  preceding  in  that  the  front  meets  the 
top  of  the  head  in  an  even,  obtuse  curve.  The  species  are 
usually  long-winged,  and  the  thorax  is  either  crested  or  rough 
and  tuberculate,  with  somewhat  prominent  and  sharp  angles. 
Quite  usually  the  hind  wings  are  brilliantly  red  or  yellow  and 
black,  sometimes  blue,  and  frequently  contrasting  in  color.  To 
this  sub-family  belong  those  species  that  fly  early  in  spring  and 

have   wintered    in 
Fig.  55.  an  immature  stage, 

ready  for  the  trans- 
formation to  the 
adult  form  as  soon 
as  the  weather  per- 
mits. Good  ex- 
amples of  such 
species  are  the 
green-striped  locust  {Ckoi'tophaga  viridifascia),  which  occurs 
over  a  large  part  of  the  United  States,  and  has  the  hind  wings 
without  strong  contrasts  ;  and  the  large,  red-winged  Hippiscus 
discoideiis,  which  is  more  southern  in  its  range,  not  extending 
north  of  New  Jersey.  Species  of  this  kind  are  most  frequent  in 
barren,  sandy,  or  partly  desert  regions,  and  few  ever  become 
injurious. 

Among  the  troublesome  forms  are  the  "  Carolina  locust,"  Dis- 
sosteria  Carolina,  and  the  long-winged  locust,  Dissosteria  longi- 
pennis  ;  the  first  found  throughout  the  United  States,  and  easily 
recognized  by  its  large  size  and  the  ample,  black,  yellow-bordered 
hind  wings  ;  the  latter  a  similar  but  somewhat  longer-winged 
western  species,  usually  confined  to  the  Rocky  Mountain  region, 
but  sometimes  migrating  for  considerable  distances  from  their 
normal  breeding-places.  These  species  deposit  their  eggs  in  the 
ground  in  the  fall  and  the  young  hatch  in  the  spring. 

The  "Carolina  locust"  is  often  met  with  in  late  fall,  clinging 
fast  to  the  tops  of  plants,  killed  by  a  fungous  disease  which 
ordinarily  keeps  the  species  within  bounds.  It  is  further  con- 
spicuous by  its  habit  of  poising  a  few  feet  from  the  surface,  and 
making  a  continuous  "  whirring"  or  rasping  sound. 

The  sub-family  Acridiince  is  one  of  great  extent,  containing 
those  grasshoppers  that  have  become  famous  by  their  evil  deeds, 


Fii;.  5.S. 


Fig.  54,  Syrbtua  adiiiirabilU.  ric;.  56,  Hippisnts  diM-i-idnii.  ]-"ig.  57,  Vissosfrira 
carn/hia.  Fig.  5S,  Schistocerca  americatia.  Fig.  59,  MiiauDplus  sfiretiis.  Fig.  60,  Mcla- 
noplus  allanis. 


THE    INSECT   WORLD.  89 

and  it  dififers  from  the  precedint;  in  havino^  the  breast  between  the 
anterior  legs  produced  into  an  obvious  tubercle  or  pointed  pro- 
cess. The  prothorax  is  usually  smooth  and  (luitc  even,  rarely 
ridged  or  crested  or  even  angulated,  and  the  hind  wings  are  not 
often  contrastingly  colored. 

The  typical  genus  Acridium  of  older  authors  contained  the 
long-winged  forms,  which,  hatching  in  great  numbers  in  their 
natural  haunts,  sometimes  find  food  insufficient,  and  are  seized 
with  a  migratory  mania  that  impels  them  to  rise,  by  what  seems 
common  consent,  and  fly  to  fresh  fields  and  pastures  new.  Such 
swarms  may  number  uncounted  millions  of  specimens,  and  they 
leave  a  wake  of  devastation  which  only  those  who  have  seen  can 
appreciate. 

The  species  described  in  biblical  history  is  the  Schistocerca 
peregrbuim,  or  true  migratory  locust,  and  is  strongly  resembled, 
except  in  size,  by  the  Schistocerca  americana  of  the  Eastern 
United  States,  which  is  common  and  sometimes  destructive  in  the 
South,  but  becomes  more  rare  northwardly,  until  in  Central  New 
Jersey  it  is  but  occasionally  seen.  In  all  the  species  oi  Acridium 
the  wings  are  longer  than  the  abdomen,  and  in  the  males  the  tip 
of  the  abdomen  is  not  swollen.  The  sexes  in  these  insects  are 
easily  distinguished,  because  the  female  abdomen  terminates  in 
four  pointed,  horny  valves,  or  pieces,  no  trace  of  which  is  found 
in  the  males. 

Perhaps  this  is  a  convenient  place  to  describe  the  life  history 
of  grasshoppers,  or  Acridiidce,  in  general.  The  eggs  are  most 
frequently  laid  in  the  ground,  though  sometimes  in  partly  de- 
cayed wood,  the  horny  valves  already  mentioned  serving  to 
make  the  holes.  The  species  that  oviposit  in  the  ground  select 
a  moderately  hard  or  compact  soil  where  obtainable,  not  too 
densely  covered  with  vegetation,  and  then  force  the  abdomen 
into  it  as  deeply  as  possible.  When  this  is  accomplished  the 
eggs  are  laid,  each  coated  with  a  gummy  secretion  which  causes 
it  to  adhere  to  its  neighbor  and  to  form  a  pod,  extending  almost 
to  the  surface.  The  hole  is  then  closed,  and  becomes  indis- 
tinguishable except  on  close  examination.  In  this  state  they 
remain  through  the  winter,  the  young  hatching  during  the  fol- 
lowing spring  or  early  summer.  The  term  nymph  rather  than 
larva  is  employed  for  these  young,  unfledged  grasshoppers,  and 


90  AN  ECONOMIC   ENTOMOLOGY. 

in  this  stage  their  traveUing  powers  are  hmited,  though  their 
appetite  is  not.  Yet  even  now  they  are  able  to  cover  consider- 
able distances  if  a  short  food  supply  makes  it  necessary.  The 
wing- pads,  which  become  visible  early  in  the  nymphal  life,  increase 
in  size  until  the  insect  is  ready  for  its  final  change,  and  when  this 
occurs  its  powers  for  destruction  are  multiplied  by  the  new  facility 
in  travelling.  In  some  species  the  wings  never  become  devel- 
oped even  in  the  adult  ;  but  these  are  easily  distinguished  from 
the  immature  stages  of  winged  forms,  because  in  the  latter  the 
rudiments  of  the  hind  wings  always  cover  those  of  the  fore- 
wings,  while  in  adults,  even  when  the  wings  are  mere  stumps, 
the  secondaries  are  always  overlaid  or  covered  by  the  others. 

Our  best-known  migrating  forms  belong  to  the  genus  Melan- 
oplus,  in  which  the  anal  extremity  of  the  males  is  enlarged  and 
swollen.  Here  we  find  the  Melanoplus  sprehcs,  or  ' '  Rocky 
Mountain  locust, ' '  which  in  years  past  has  caused  ruin  in  many 
States  west  of  the  Mississippi,  and  even  yet  does  much  injury 
and  periodically  threatens  disaster.  The  home  of  this  species, 
about  which  volumes  have  been  written,  is  on  the  high,  dry, 
eastern  slopes  of  the  Rocky  Mountains,  and  in  some  regions 
west  of  these  mountains  in  Idaho  and  Utah.  There  it  breeds 
abundantly  each  year,  frequently  extending  into  the  adjacent 
regions  to  obtain  food  and  maintaining  itself  for  some  time.  As 
a  result  of  any  unusual  increase  in  numbers  with  a  corresponding 
failure  of  food-supply,  emigration  may  become  necessary,  and  the 
long,  broad  wings  of  the  species  suffice  to  carry  it  even  to  the 
Mississippi  River,  ranging  north  and  south  from  Minnesota  to 
Texas.  But  in  these  moist  eastern  regions  the  insect  cannot 
thrive,  and  from  millions  of  eggs  laid  only  a  small  proportion  of 
weakly  larvae  appear,  which  usually  die  before  they  mature. 

An  allied  but  shorter-winged  form  is  the  Melanoplus  atlanis, 
or  "lesser  locust,"  which  occurs  commonly  over  all  the  more 
northern  United  States,  while  the  M.  fenuir-riibrian,  or  "red- 
legged  locust,"  is  much  the  most  common  eastern  species,  some- 
times doing  considerable  injury  to  crops. 

Among  the  more  common  short-winged  forms  we  have  in  the 
East  species  of  Paroxya,  in  which  the  males  are  smaller  and 
ready  fliers,  the  females  much  larger,  with  wings  covering  half 
the  abdomen,  and  used  rather  as  aids  in  leaping  than  as  organs 


THE    INSECT    WORLD. 


91 


of  actual  flight.  The  species  of  Pezotettix  and  aUied  genera  are 
short-winged  in  both  sexes,  are  of  medium  or  small  size,  and 
prefer  cool  or  shady  spots  on  mountain  sides,  among  rocks,  at 
the  edges  of  woods,  or  in  similar  localities,  hence  never  become 
economically  important.  The  species  are  most  numerous  in  the 
West  and  South. 

F'iG.  61. 


Lubber  grasslioppers. — a,  Dictyophorus  rcticiilatis  :  b,  />'/  iu/iys/o/u  iiiagim. 

Two  very  large  and  clumsy  species  occur,  both  known  as 
"lubbers;"  one  in  Florida,  short-winged,  yellow  and  black,  is 
Dictyophorus  retiadatis, — the  other,  a  Western  plains  species, 
dirty-brown  in  color,  and  with  mere  rudiments  of  wings,  also 
known  as  the  ' '  Buffalo  grasshopper, ' '  is  Brachystola  viagna. 

Last  to  be  mentioned  in  this  series  are  the  "grouse  locusts," 
or  TettigincB.     These  remarkable  little  creatures  have  the  pro- 


92 


AN  ECONOMIC   ENTOMOLOGY. 


thorax  very  much  developed  and  extended  backward  so  as  to 
cover  a  large  part  or  even  all  of  the  abdomen.  They  frequent 
banks  of  streams  and  moist  places,  resembling  in  color 
Fig.  62.  j-j^g  dead  leaves  or  muddy  flats  where  they  often  occur, 
and  they  are  powerful  leapers.  Many  of  the  species 
are  found  as  adults  early  in  spring,  while  I  have  found 
others  in  September.  None  of  them  are  known  to  be 
injurious. 

REMEDIES. 

The  question  of  remedies  against  the  ' '  locust, ' '  or 

Tettix.  short-horned  grasshopper,  is  an  important  one,  not 
always  easy  of  solution.  As  the  country  is  brought 
into  more  complete  cultivation  the  ' '  grasshopper' '  pest  will  natu- 
rally decrease,  injury  from  the  migrating  forms  only  remaining  to 
be  dreaded. 

In  the  general  life  history  it  was  said  that  a  large  proportion 
of  the  eggs  are  laid  in  fall,  remaining  unhatched  during  the 
winter.  The  young  nymph,  or  larva,  is  a  feeble  insect,  able  to 
dig  to  the  surface  through  the  way  opened  by  the  pod,  or  through 
loose  soil,  but  scarcely  otherwise.  Fall-plowing  the  infested  land 
is  therefore  a  most  effective  remedy.  If  the  pods  are  deeply  cov- 
ered, the  young  die  attempting  to  get  to  the  surface  ;  if  lightly 
covered  or  exposed,  their  natural  enemies  find  them  easily  ;  and 
when  the  pods  are  broken,  rain  and  sunshine  induce  decay  or 
disease,  and  the  eggs  never  hatch.  Where  grasshoppers  other 
than  the  migratory  forms  are  troublesome,  systematic  fall-plowing 
will  effect  a  prompt  reduction  in  their  numbers.  Special  or  lim- 
ited localities,! like  cranberry  bogs,  are  sometimes  infested,  and  in 
such  cases  turkeys  are  effective.  They  prefer  grasshoppers  to 
almost  any  other  food,  and,  if  allowed  to  run  where  such  abound, 
will  eat  nothing  else.  In  some  cases  the  arsenites  may  be  used 
to  protect  crops  which  are  easily  sprayed,  and  occasionally 
"  driving"  will  answer  for  the  fledged  insects. 

Larval  forms  in  grass  or  short  vegetation  can  be  collected  in 
large  pans  or  "hopper-dozers,"  drawn  by  men  or  horses,  and 
coated  with  coal-tar,  crude  petroleum,  or  other  sticky  substance, 
and  of  all  these  the  crude  petroleum  is  to  be  preferred. 

As  against  the  migratory  forms  in  their  permanent  breeding 
grounds,  I  have  no  suggestion  to  make  here.     The  subject  has 


THE    INSECT    WORLD. 


93 


been  treated  at  great  length  in  the  reports  of  the  U.  S.  Entomo- 
logical Commission  and  of  the  U.  S.  Department  of  Agriculture, 
and  these  must  be  consulted  :  the  methods  discussed  and  recom- 
mended are  too  numerous  for  reference  here.  In  the  invaded 
regions  foil  plowing  to  destroy  the  eggs  and  the  use  of  the 
"hopper-dozers"  on  the  young  arc  indicated. 

Under  some  circumstances,  when  the  number  of  grasshoppers 
is  not  too  great,  they  may  be  destroyed,  or  a  large  measure  of 
protection  may  be  secured,  by  tempting  them  with  poisoned 
bran,  of  which  they  seem  to  be  rather  fond.  It  should  be  com- 
posed of  bran  and  Paris  green,  at  the  rate  of  one  part  of  Paris 
green  to  fifty  by  weight  of  bran,  thoroughly  moistened  with 
sugar  water.  Cabbage  patches  can  often  be  protected  in  this 
w^ay  against  grasshoppers  that  come  from  uncultivated  land,  and 
there  are  other  cases  where  such  a  measure  is  of  value.  Indi- 
vidual judgment  must  determine  those  cases. 

The  LoaistidcB  are  "long-horned  grasshoppers,"  "meadow 
grasshoppers,"  and  "katydids,"  distinguished  at  once  by  very 
long,  slender  antennae,  rarely  shorter  than,  and  usually  much 
exceeding,  the  body.  They  are  green  in  color  as  a  rule,  with 
slender  legs  and  thin  wings,  and  we  find  them  a  vast  array  of  mu- 
sicians,— always  the  males  only, — the  sound-producing  structure 
occupying  a  triangular  area  at  the  base  of  the  fore-wings,  where 
they  overlap.  Here  one  or  more  of  the 
veins  is  elevated  and  ridged  on  each  wing, 
and  by  rubbing  these  ridged  surfaces  to- 
gether a  strident  sound  is  produced,  in- 
tensified by  a  membrane  tightly  stretched 
between  them.  The  pitch  and  volume  of 
the  ' '  song' '  are  regulated  by  the  develop- 
ment of  veins  and  membrane  as  well  as  of 
the  tegmina,  no  two  species  being  alike  in 
this  respect.  Special  students  of  the  family 
soon  learn  to  recognize  the  sounds  made 
by  the  different  species  as  certainly  as  or- 
nithologists know  birds  by  their  song.  The 
ears  through  which  the  songs  appeal  to  the  courted  females  and 
competing  males  are  situated  on  the  fore  tibiae,  and  are  essentially 
like  the  same  organs  found  on  the  abdomen  of  the  Acridiida. 


Fig.  63. 


Overlapping  portion  of 
the  base  of  the  wing  in  Cono- 
cephalus ,s\\o\\\t\p,  the  ridged 
veins  and  sound-producing 
organ. 


94 


AN  ECONOMIC   ENTOMOLOGY. 


Another  feature  peculiar  to  this  family  is  the  exserted,  promi- 
nent, blade-like  ovipositor  of  the  female,  which  indicates  an  es- 
sentially lifferent  method  of  oviposition.  This,  in  fact,  exists, 
for  the  eggs  are  mostly  laid  in  plant  tissue, — usually  in  the  stems 
of  reeds  and  grasses,  among  which  some  forms  abound, — some- 
times in  woody  tissue  ;  rarely  in  leaves,  the  edges  being  split  to 
receive  them  ;  and  only  occasionally  are  they  laid  externally. 
Certain  cricket-like  species  are  exceptions,  and  oviposit  in  the 
ground. 

The  most  prominent,  from  their  large  size,  are  the  species 
loosely  termed  "katydids," — insects  which  are  familiar  by  their 
song,  but  are  not  always  personal  acquaintances,  because  they 
are  most  active  and  noisy  in  the  evening,  and  prefer  trees  and 
shrubs  to  more  modest  plants.  The  true  ' '  katydid' '  is  Cyr- 
tophylliim  concavHJU,  much  the  heaviest  in  build  of  all  our  spe- 
cies, with  very  broad  concave  wing-covers  and  an  unusually 
developed  sound-producing  structure.  In  fact,  the  entire  fore- 
wings  are  immense  sounding-boards,  enabling  the  insect  to  make 
itself  heard  at  great  distances.  It  produces  its  characteristic  note 
three  or  four  times  in  succession,  with  slight  intervals  only,  bear- 
ing thus  a  semblance  to  "  Ka-ty-did"  or  "  Ka-ty-did-n't :"  oc- 
casionally it  merely  rasps  out  ' '  Ka-ty. ' ' 

This  species  lays  its  ovate,  slightly  convex  eggs  into  the  twigs 
or  trunks  of  trees  late  in  fall,  and  the  young  appear  during  the 
early  summer  following. 

One  of  the  most  common  of  the  large  species,  found  over  a 
great  part  of  the  Northern  United  States,  is  the  Microcentruni 
retinervis,  replaced  in  the  South  by  the  allied  M.  laurifolium, 
which  lay  their  large  eggs  externally  in  regular  rows  on  the  edges 
of  leaves,  on  twigs,  or  on  any  sort  of  likely  or  unlikely  place, — 
e.g. ,  the  pulley-strap  of  a  sewing-machine.  The  Southern  spe- 
cies is  the  more  common,  and  in  Florida  becomes  injurious  to 
young  orange-trees  by  eating  the  foliage.  They  can  be  kept  in 
check  on  such  trees  by  collecting  and  destroying  the  eggs  during 
winter,  by  collecting  the  insects  themselves,  or  by  spraying  the 
foliage  with  one  of  the  arsenites. 

The  genus  Scudderia  contains  smaller,  narrower-winged  spe- 
cies, in  which  the  tegmina  are  not  expanded  in  the  middle  and 
the  ovipositor  is  curved  sharply  upward.     They  frequent  shrubs 


P'lG.   65. 


The  Southern  katydid,  Microcentrum  /auri/oliitni. — i,  the  female  adult;  la,  eggs 
laid  on  leaves  and  twigs  of  orange  ;  lb,  the  young  katydids  ;  2  and  2a,  female  and  male 
Eitpflmus  mirabilis  :  parasites  on  the  eggs  at  2h. 

95 


96 


A.V  ECONOMIC   ENTOMOLOGY. 


and  low  vegetation,  often  near  marshy  or  boggy  land  in  sandy 
districts.  The  eggs  are  sometimes  laid  in  the  edges  of  leaves, 
singly,  between  the  upper  and  under  surfaces,  and  are  so  'tKin 
that  they  can  be  perceived  with  difficulty  only.  They  swell, 
however,  very  considerably  before  hatching. 

In  New  Jersey  species  of  this  genus  sometimes  do  great  injury 
on  cranberry  bogs,  eating  out  the  seed-capsule  of  the  berries  and 
rejecting  the  pulp.  A  single  specimen  may  eat,  at  one  meal,  the 
seed-capsules  of  five  or  six  berries,  and  in  a  week  half  a  peck  may 
be  destroyed  or  rendered  unmarketable. 

Turkeys  exercise  a  good  effect  here  also,  the  insects  recog- 
nizing the  presence  of  an  enemy  in  a  very  short  time  and  leaving 
the  bogs.  A  good  method  of  lessening  the  injury  is  to  burn 
over  the  ground  around  the  infested  district  to  destroy  the  eggs. 
Nature  itself  does  much  to  check  increase,  the  number  of  speci- 
mens averaging  about  the  same  from  year  to  year  ;  so  any  in- 
telligent interference  by  man  must  be  to  his  advantage,  and  a 
destruction  of  the  dropped  leaves,  especially  of  oak,  which  may 
contain  eggs,  will  be  a  gain. 

Next  in  size  and  musical  ability  are  the  "cone-nosed  grass- 
hoppers," Conocephaliis,  with  very  long  antennae,  very  long  hind 
legs,  very  long  and  narrow  fore-wings,  and  a  pointed,  conically- 
projecting  head.  In  the  female  the  ovipositor  is  as  long  as  or 
longer  than  the  rest  of  the  body.  These  insects  may  be  quite 
common,  yet  rarely  seen,  because  of  their  resemblance  to  the 
reeds,  grasses,  and  other  vegetation  among  which  they  live. 
They  do  not  become  active  until  late  in  the  afternoon,  and  may 
be  located  by  their  loud,  shrill,  long-sustained  song.  Then, 
quietly  waiting  until  it  is  resumed,  the  male  may  be  seen  with 
wings  rapidly  vibrating  and  usually  near  his  mate,  for  whose 
benefit  all  this  concert  is  produced.  The  eggs  are  laid  in  the 
stalks  of  the  reeds  and  grasses  among  which  the  insects  live  ; 
hence  late  mowing  of  infested  meadows,  or  burning  over,  during 
the  winter,  swampy  or  marshy  spots  in  which  they  breed  will 
keep  them  in  check  when  they  become  troublesome. 

Close  relatives  of  the  above  are  the  smaller,  green  meadow 
grasshoppers,  largely  members  of  the  genera  Oi'chelimuni  and 
Xiphidium, — the  former  with  curved,  the  latter  with  a  straight 
ovipositor  in  the  female.     These  species  all  prefer  moist  lands 


V\G.   68. 


I'lc.   64. 


Fig.  66. 


Fig.  67. 


Fig.  04.  the-  katydid,  Cyrtopliyllum  coiicavum.  Fig.  66,  Oiclulimum  vulgare,  male. 
Fig.  67,  Orchrlmmm  vulgare,  female,  from  side.  Fig.  68,  Mormon  cricket,  Ancbrui 
simplex :  a,  female  ;  b,  c.  anal  parts  of  the  male. 


THE    IXSECT   WORLD. 


97 


with  rank  vegetation  abounding  in  reedy  grasses,  in  which  they 
lay  their  eggs,  and  among  which  they  sport  and  sing,  except 
during  midday.  They  are  especially  fond  of  eating  the  seeds  of 
grasses,  and  sometimes  become  troublesome  from  this  habit. 
The  late  mowing  and  burning  suggested  for  Conocephahis  will 
answer  in  this  case  as  well. 

We  find  quite  a  departure  from  the  normal  type  in  a  series  of 
wingless  or  short-winged  species  erroneously  called  "crickets," 
and,  more  correctly,  "shield-backed  grasshoppers."  In  the 
Eastern  United  States  these  are  rare,  found  under  stones  or  rub- 
bish in  woods,  sometimes  in  caves.  Some  are  blind,  and  others 
have  equally  interesting  structures,  but  are  of  little  or  no  economic 
importance.  From  their  peculiar  humped  shape  some  are  known 
as  "camel  crickets."  In  the  West  these  species  become  more 
abundant,  and,  at  the  base  of  the  Rocky  Mountains,  extending 
up  into  the  foot-hills,  they  find  their  true  home.  Here  the 
' '  Mormon  cricket, ' '  Anabnis  simplex,  occasionally  multiplies  so 
greatly  that  it  migrates  to  the  plains  below,  destroying  everything 
in  its  path.  As  the  insects  are  wingless  they  move  but  slowly, 
and  may  be  often  checked  by  ditching  in  their  path.  They  are 
very  pugnacious,  with  cannibalistic  tendencies,  falling  upon  and 
devouring  any  injured  comrade,  and  indulging  in  free  fights  when 
driven  into  a  corner.  A  plowed  field  in  their  course  forms  a 
barrier  difficult  for  them  to  pass,  and  in  such  an  army  of  the 
insects  can  be  materially  reduced  or  exterminated  by  means  of 
heavy  rollers. 

Yet  more  cricket-like  are  the  clumsy,  large-headed  species  of 
Stenopalmatus ,  known  on  the  Pacific  Coast,  where  they  occur, 
as  "sand-crickets."  They  are  sometimes  quite  plentiful,  but 
have  not  been  known  as  injurious,  since  they  are  partly  carniv- 
orous in  their  food-habit. 

The  crickets  belong  to  the  family  Gryllidcr,  and  differ  from  the 
Lociistid(B  in  that  they  have  the  wings  laid  flat  on  the  back, 
the  fore-wings  abruptly  bent  down  at  the  sides,  and,  in  the  female, 
have  the  ovipositor  cylindrical  or  needle-like,  instead  of  flattened 
or  sword-like.  This  ovipositor  usually  has  a  little  enlargement, 
somewhat  resembling  a  spear-head,  just  before  the  tip,  which 
facilitates  placing  the  ^%'g.  The  males  are  even  greater  musicians 
than  the  Locustidce,  the  entire  wing-covers  being  modified  into  a 

7 


98 


AN  ECONOMIC   ENTOMOLOGY. 


stridulating-  organ.  Here  the  sound  is  produced  by  the  ridged 
edge  of  one  wing-cover  scraping  over  the  ridged  veins  of  the 
other,  setting  into  vibration  the  membraneous  spaces  in  both 
wings.     The  ear  is  situated  on  the  fore-tibia,  as  in  the  LocustidcB. 


Fig.  69. 


A  sand-cricket,  Stenopalmatus  species. 


The  mole-crickets  are  curious,  subterranean  creatures,  with 
small  heads  and  powerful  forelegs,  developed  somewhat  like  the 
corresponding  organs  in  the  mole.  The  larger,  more  common 
species  belong  to  the  genus  Gryllotalpa,  and  are  more  frequent 


Mole-crickets,  Gryllotalpa  species. 


in  the  South  and  Southwest,  where  they  occasionally  injure  field 
crops.  They  are  strictly  nocturnal  in  habit,  and  remain  during 
the  day  in  their  burrows,  in  which  a  chamber  is  excavated  to 
contain  the  eggs. 


THE    II^SECT    WORLD. 


99 


When  they  are  sufficiently  numerous  to  be  troublesome,  the 
insects  may  be  attracted  to  the  sweetened  and  poisoned  bran 
mixture  heretofore  mentioned,  and  this  will  usually  check  injury. 

The  field-crickets,  species  of  Grylhts,  well  known  to  all,  are 
found  nearly  everywhere,  even  in  houses.     They  are  usually  dark- 
brown  or  blackish  in  color,  with  large,  broad  heads,  and  rather 
short  though  power- 
ful hind  legs.     They  ^''^''-  '2 
are  very  active,  and 
jump  about  so  errat 
ically  that  it  is   not                          u  |  a 

Fig 


A     field-cricket,    Gryllm 
species. 


The  tree-cricket,  fif<rt«////(i  iiiveui,  female  from 
the  side,  male  from  above.— a,  blackberry  cane 
showing  egg  punctures;  b,  the  same,  split,  to 
show  the  arrangement  of  the  eggs  ;  c,  egg,  very 
much  enlarged  ;  d,  its  tip,  yet  more  enlarged. 


always  an  easy  task  to  capture  the  specimens.  There  is  less 
trouble  in  the  fall,  when  the  female  is  ovipositing  in  warm,  sandy 
spots,  and  the  male  is  watching  her,  keeping  up  a  constant  sing- 
ing during  the  operation.  As  a  rule  the  species  winter  in  the  &gg 
state,  but  occasionally  nymphs  and  adults  survive,  and  a  solitary 
and  melancholy  chirp  in  spring  now  and  then  tells  of  such  a  speci- 
men.     Most  of  the  species  are  plant-feeders,  yet  rarely  attack 


loo  AN   ECONOMIC   ENTOMOLOGY. 

green  vegetation  ;  fruits  like  cranberries  are  occasionally  eaten 
into,  and  sometimes  roots  or  tubers  are  attacked  ;  but  the  injury- 
is  rarely  of  economic  importance. 

Crickets  are  pugnacious  as  a  rule,  occasionally  eating  their 
companions,  or  such  other  soft-bodied  specimens  as  fall  in  their 
way,  while  "cricket-fights"  are  not  unknown  in  the  lists  of  sports. 

The  tree-crickets,  CEcanthus,  are  more  slender  and  graceful 
than  any  of  the  preceding,  and  more  ready  fliers.  They  are 
green,  yellowish,  or  gray  in  color,  and  live  on  trees  or  shrubs, 
feeding  chiefly  upon  plant-lice  and  other  soft-bodied  insects  of 
various  kinds.  They  lay  their  eggs  in  the  stems  of  pithy  plants 
like  blackberry  and  raspberry,  puncturing  the  wood  by  means  of 
their  powerful,  auger-like  ovipositor.  Quite  often  these  punctured 
canes  die,  but  practically  little  damage  is  done  unless  the  insects 
are  much  more  abundant  than  I  have  ever  seen  them.  In  either 
blackberry  or  raspberry  canes  the  punctures  are  so  readily  seen, 
especially  in  spring,  that  they  can  be  cut  out  while  trimming  and 
the  whole  brood  destroyed.  This  is  indeed  the  best  method  of 
dealing  with  these  graceful  creatures,  who  have  little  resemblance, 
except  in  essential  structure,  to  their  lowly  and  sordid  cousins  of 
the  field. 


CHAPTER    V. 

THE    HEMIPTERA,   OR    BUGS. 

The  term  Hemiptcra  means  half-winged,  and  is  primarily  ap- 
plied to  insects  in  which  the  wing-covers  are  partly  thick  and 
leathery  and  partly  thin  and  membraneous,  the  latter  texture 
obtaining  towards  the  apex.  The  term  becomes  inapplicable, 
however,  in  those  insects  which,  agreeing  otherwise  in  structure 
with  the  half-winged  species,  have  the  anterior  wings  of  the  same 
texture  throughout,  whether  like  that  of  the  hind  wings  or  de- 
cidedly thicker.  To  distinguish  the  two  series  the  terms  Heter- 
optera,  meaning  "different  wing,"  and  Homoptera,  meaning 
"equal  wing,"  are  applied.  Besides  these  there  is  another 
division  which  has  no  wings  at  all,  and,  owing  to  the  fact  that 


THE    INSECT   WORLD.  lOi 

the  species  live  and  feed  upon  animals,  .this  is  called  Parasitica. 
All  these  agree,  however,  in  the  essential  character  of  the  order, 
which  is  found  in  the  structure  of  the  mouth  parts.  Throughout 
all  series  we  find  the  head  prolonged  into  a  jointed  beak  or  ros- 
trum, obsolete  only  in  the  Parasitica,  and  within,  protected  by 
it,  is  a  series  of  three  or  four  slender,  needle-Hke  lancets.  The 
beak  is  open  in  front,  and  the  lancets  may  be  protruded  at  the 
tip.  In  most  species,  when  the  insect  is  feeding,  the  lancets  are 
so  deeply  inserted  that  the  beak  bends  at  or  about  the  middle, 
leaving  them  entirely  free  except  at  the  tip.  In  other  cases, 
among  predaceous  types,  the  beak  is  too  rigid  to  bend  thus,  and 
it,  as  well  as  the  lancets,  is  forced  into  the  tissues  upon  which 
the  insect  feeds.  It  is  to  insects  of  this  order  only  that  the  ento- 
mologist applies  the  term  ''bug'''  and  when  he  uses  that  word 
he  always  refers  to  one  of  the  Hemiptera.  It  has  been  indicated 
that  the  creatures  gain  their  food  by  piercing  and  sucking,  and 
this  is  a  radically  different  method  from  anything  found  hereto- 
fore. We  have  now  insects  that  are  incapable  of  chewing  food, 
and  subsist  only  upon  liquids  which  must  be  drawn  from  living 
tissue,  be  it  animal  or  vegetable.  A  large  proportion  of  the  spe-. 
cies  is  injurious  ;  but  there  are  also  groups  of  predaceous  habit, 
feeding  upon  other  insects  in  whole  or  in  part,  that  may  be  con- 
sidered beneficial.  In  their  development  the  insects  belong  to 
that  series  in  which  the  metamorphosis  is  incomplete  ;  but  there 
is  an  exception  in  the  males  of  certain  bark-lice,  where  there  is  a 
real,  quiescent  pupal  stage. 

Before  going  further  on  this  subject  it  is  necessary  to  refer  to 
the  peculiar  little  species  known  as  Thrips,  and  belonging  to  the 
family  Thripidce.  They  are  now  as  a  rule,  and  properly,  sepa- 
rated from  the  true  Hemiptera  under  the  ordinal  terms  Thysan- 
optera,  meaning  fringe-winged,  or  Physopoda,  meaning  bladder- 
footed.  They  are  always  small  in  size,  slender,  active,  with  the 
head  so  narrow  that  they  seem  pointed  at  both  ends.  The  wings 
are  laid  longitudinally  on  the  back,  and  are  very  narrow,  trans- 
parent, without  veins  or  with  mere  rudiments,  but  with  lengthy 
fringes,  which  give  them  a  characteristic  and  peculiar  appearance. 
The  feet  are  not  terminated  by  pointed  claws  as  usual,  but  by 
small,  bladder-like  dilations  of  the  terminal  joints.  They  run 
and  fly  readily,  and  some  of  them  jump  much  as  do  spring-tails. 


AN  ECONOMIC  ENTOMOLOGY. 


Fig 


Thrips  tritici. — b,  antenna  ;  c,  a  tarsus. 


The  mouth  structure  is  in  some  respects  intermediate  between 
that  of  the  true  bugs,  as  already  described,  and  that  of  the  man- 

dibulate  type  ;  but  there  are  no 
true  mandibles,  and  the  insects  can- 
not chew  their  food,  hence  come 
naturally,  for  our  purpose,  into  this 
order. 

The  species  of  Thrips  are  often 
seriously  injurious  to  vegetation. 
They  sometimes  attack  onions  in 
great  numbers,  puncturing  the  suc- 
culent leaves,  and  everywhere  leav- 
ing a  small  yellow  dot.  As  these 
increase  in  number  the  leaf  loses 
vitality,  the  top  itself  turns  yellow, 
and  in  serious  cases  the  rich  green 
of  a  normal  onion  field  is  changed 
to  a  peculiar,  sickly  yellow.  The 
insect  is  yellowish  when  immature,  and  blackish-brown  when  the 
wings  are  developed. 

Cabbages  sometimes  suffer  in  a  similar  manner.  The  insects 
in  this  case  are  yellow,  and  congregate  in  large  numbers  on  the 
lower  side  of  the  outer  leaves,  and  as  these  become  dry  and 
wither  they  move  to  those  nearer  the  centre. 

Grass  is  often  attacked  by  them,  and  here  they  cause  one 
form  of  what  is  known  as  ' '  silver  top. ' '  Wheat,  oats,  rye,  and 
other  grains  are  often  victimized,  and,  indeed,  there  are  few 
plants  not  liable  to  infestation,  even  tobacco  appearing  among 
the  sufferers. 

These  insects  thrive  best  in  hot,  dry  weather,  hence  become 
more  dangerous  as  the  plants  are  less  able  to  resist  them,  and 
our  effort  must  be  in  the  direction  of  aiding  the  crop  as  well  as 
destroying  the  insects.  Contact  poisons  are  indicated  here,  as 
against  the  true  Hemiptera,  and  either  the  kerosene  emulsion, 
diluted  ten  times,  or  the  whale-oil  soap,  one  pound  in  four  gal- 
lons of  water,  is  satisfactory.  Plenty  of  cold  water,  where  it  is 
available,  acts  very  well  on  a  small  scale  ;  but  no  application  is 
feasible  on  large  fields  of  cereals  or  grass.  Here  stimulation  only 
can  be  resorted  to  to  give  the  plants  additional  vigor,  and  har- 


THE    INSECT    WORLD.  103 

vesting  should  be  done  as  soon  as  possible  to  check  the  increase 
of  the  pests. 

Many  species  of  Thrips  are  found  on  flowers,  many  also  under 
the  bark  of  trees,  and  some  forms  are  said  to  be  predaceous. 
Their  life  habits  are  not  well  known,  but  a  large  number  winter 
in  the  adult  stage  under  such  shelter  as  they  can  find, — hence, 
cleanliness  on  the  farm  is  indicated. 

For  a  better  understanding  of  the  characters  of  the  more  typi- 
cal Hemjptera,  we  will  take  up  the  families  separately  ;  and  first 
the  Parasitica.  By  taking  up  this  series  before  the  others  it  is 
not  to  be  understood  that  they  are  higher  in  the  scale,  nor,  on 
the  other  hand,  much  lower  in  type  ;  but  it  is  simply  a  matter 
of  convenience.  Parasites,  because  of  their  habits,  are  often  said 
to  be  '  *  low  ;' '  but  it  is  a  question  whether  this  is  true,  because 
parasitism  is  an  acquired  character,  and  the  insects  are  really 
much  specialized  for  their  habit  of  life  and  well  adapted  to  it. 
We  have  in  a  previous  chapter  considered  the  biting  lice,  and 
found  that  they  feed  more  particularly  upon  surface  structures. 
The  sucking  lice,  as  the  term  indicates,  obtain  their  food  by 
piercing  the  skin  and  sucking  the  animal  juices  or  blood.  The 
mouth  differs  from  that  of  the  other  bugs  in  that  the  proboscis 
is  fleshy  and  unjointed,  capable  of  being  withdrawn  into  the  head 
or  extended,  and  within  it  are  two  protrusible  lancets  only.  At 
its  base  is  a  circlet  of  hooks,  by  means  of  which  the  insect  an- 
chors itself  firmly  in  the  skin  of  the  infested  animal.  The  legs 
are  "scansorial,"  or  fitted  for  climbing, — that  is  to  say,  they  are 
short,  heavy,  set  at  the  sides  of  the  thorax,  and  the  tarsus  is 
modified  into  a  stout,  slightly  curved  claw,  opposed  like  a  thumb 
to  the  end  of  the  tibia,  which  in  turn  is  broadened  at  the  tip  and 
a  little  excavated.  Thus,  between  the  end  of  the  tibia  and  the 
tarsus,  the  insect  is  able  to  grasp  a  hair  so  tightly  that  it  is  some- 
times easier  to  pull  it  from  the  skin  than  to  dislodge  the  parasite. 
Here  we  have  another  example  of  insects  that  do  not  change  in 
appearance  throughout  their  life  :  they  simply  increase  in  size 
and  become  adult  when  the  sexual  organs  are  fully  developed. 
Warm-blooded  animals  only  are  infested  by  these  sucking  lice, 
man  being  included  under  this  general  term. 

Three  species  are  found  on  the  human  animal:  one,  Pediculus 
capitis,  infesting  the  head,  glues  its  eggs,  which  are  known  as 


I04 


AN  ECONOMIC  ENTOMOLOGY. 
¥\G.  74. 


Hog-louse,  Hcematopinits  urius :  the  scansorial  claw  at  c. 


Fig.  75. 


Ox-louse,  HcFtnatopinns  eurystemus :  b,  mouth  opening  ;  c,  d,  anal  details  ;  ^,  egg 
attached  to  a  hair. 


THE    INSECT    WORLD. 


105 


"nits,"  to  the  hair;  one,  Pediculus  vestivicnti,  found  on  the 
body,  knt)\vii  as  the  "body-louse,"  or  to  soldiers  as  "gray- 
backs,"  lives  in  and  lays  its  eggs  in  the  seams  of  clothing,  where 
they  are  protected  ;  the  last,  Phthirins  inguinalis,  known  as  the 
"crab-louse,"  infests  the  pubic  region  and  armpits.  The  latter 
fastens  its  eggs  to  the  hair  among  which  it  lives,  and  this  is  per- 
haps the  general  rule  throughout  the  series. 

Domestic  animals  of  all  kinds  are  infested  by  lice  ;  but  it  is  not 
necessary  to  study  the  species  in  detail,  since  their  habits  are 
much  the  same,  and  the  method  of  treatment  is  identical.  For 
the  head-louse  on  man  nothing  is  better  than  a  thorough  appli- 
cation of  lard,  vaseline,  or  other  greasy  material.  It  should  be 
applied  at  least  twice  at  intervals  of  a  few  days,  because  the  treat- 
ment does  not  kill  eggs,  and  eggs  unhatched  at  the  first  treat- 
ment would  not  be  affected. 

As  against  the  body-louse,  the  application  of  mercurial  oint- 
ment in  the  seams  of  the  clothing  answers  every  purpose.  This 
has  proved  effective  in  camps  and  hospitals,  where  the  insects 
sometimes  increase  with  marvellous  rapidity. 

As  against  the  "crab-louse,"  the  mercurial  ointment  may  be 
applied  directly  to  the  infested  spots,  and  here  also  several  ap- 
plications are  necessary  to  reach 
the  insects  as  they  hatch  from  the  Fu;.  76. 

eggs.  Their  vitality  is  great,  and 
that  of  the  eggs  is  yet  greater. 
Clothing,  no  matter  how  carefully 
washed,  may  still  remain  infested 
with  eggs,  protected  as  they  are 
in  the  seams,  unless  actual  boiling 
is  continued  for  a  considerable 
period  of  time.  Where  lice  infest 
animals  the  latter  can  sometimes 
be  cleared  by  simply  giving  them  crab-iouse,  Phthh-ii.s  in^mnaiis. 
an  opportunity  to  dust  themselves. 

Dogs,  donkeys,  less  frequently  horses,  and  other  animals,  may 
be  often  seen  in  dusty  roads,  rolling  about  in  evident  enjoyment, 
and  one  result  of  this  powdering  is  a  comparative  freedom  from 
insect  parasites  for  some  time  thereafter.  Infested  animals  may 
be  treated  as  suggested  for  the  head-lice  in  man,— that  is,  some 


lo6  AN  ECONOMIC  ENTOMOLOGY. 

heavy  oil  or  grease  should  be  applied  thoroughly.  It  will  add 
to  the  effect  of  the  mixture  if  a  little  carbolic  acid  is  added,  but 
it  is  not  essential,  though  desirable  to  prevent  rancidity  if  animal 
fat  is  used.  The  kerosene  emulsion,  used  with  a  brush  or  curry- 
comb in  cleaning  animals,  is  also  effective  ;  in  fact,  the  treatment 
suggested  for  the  biting  lice  is  also  applicable  here. 

The  section  Homoptera  contains  scale-insects,  bark-lice,  mealy 
bugs,  plant-lice,  tree-hoppers,  leaf-hoppers,  frog-hoppers,  and 
others  whose  very  names  proclaim  their  character.  Nowhere  do 
we  find  predaceous  forms,  or  such  as  can  be  accounted  beneficial 
to  the  agriculturist.  To  be  sure,  we  have  among  the  Coccids  the 
cochineal  and  lac  insects,  but  these  are  fully  as  injurious  as  any 
other  to  plant  life,  and  are  useful  simply  because  man  is  able  to 
make  better  use  of  them  than  of  the  plants  upon  which  they  feed. 

The  family  Coccidce  includes  scale-insects  and  mealy  bugs,  cu- 
rious in  their  life  history  as  well  as  injurious  to  cultivated  plants. 
The  males,  unlike  other  Hemiptera,  have  a  complete  metamor- 
phosis and  only  a  single  pair  of  wings,  the  secondaries  disap- 
pearing or  reduced  to  mere  hooks.  They  are  singular,  fur- 
thermore, in  that  the  mouth  parts  are  replaced  in  the  adult  stage 
by  a  pair  of  eyes.  The  female  is  always  wingless  throughout  her 
entire  life,  generally  grub-like  and  stationary,  covered  with  some 
sort  of  waxy  scale  or  by  a  powdery  or  cottony  secretion. 

Mealy  bugs  derive  their  name  from  the  fact  that  they  are  cov- 
ered by  a  white,  powdery  substance,  which  is  really  a  granulated 
wax  and  a  secretion  of  the  insects  themselves.  They  move  about 
freely,  and  are  furnished  with  all  sorts  of  odd  processes  at  the 
sides  of  the  body,  or  with  long  filaments  at  the  end.  They  are 
not  usually  common  in  the  North  except  in  greenhouses  and  on 
in-door  plants,  but  become  more  abundant  southward,  where  out- 
door plants  are  also  infested,  orange-trees  in  Florida  being  par- 
ticularly troubled.  To  this  series  of  mealy  bugs  the  cochineal 
insect,  Cocciis  cacti,  belongs.  It  is  a  native  of  Mexico,  but  has 
been  cultivated  in  other  countries,  feeding  upon  species  of  cac- 
tus. Specimens  have  been  found  in  Florida,  and  it  is  more  than 
likely  that  it  occurs  not  uncommonly  in  the  semitropical  part  of 
the  peninsula.  It  also  occurs  in  California.  The  dye  is  simply 
the  immature  female  insect,  which  is  brushed  off  the  plants, 
killed,  and  dried,  and  has  never  been  equalled  for  brilliancy  and 


THE    LWSECT   WORLD. 
Fig.  77. 


107 


Fig.  7S. 


Fig.  79. 


Cochineal  and  mealy  bugs. — Fig.  77,  cochineal,  Coccus  cacti,  on  cactus.  Fig.  78, 
b,  adult  male;  c,  adult  female,  with  cottony  masses  removed.  Fig.  79,  mealy  bug, 
Dactylopius  destructor.     Fig.  80,  Dactylopius  longifilis  :  a,  the  larva  ;  b.  the  winged  male. 


Io8  AN  ECONOMIC  ENTOMOLOGY. 

permanence.  Aniline  dyes  and  colors  are  superseding  it,  how- 
ever, because  of  their  cheapness  and  the  greater  ease  with  which 
they  may  be  obtained. 

Mealy  bugs  are  easily  destroyed  by  contact  poisons,  almost 
any  soapy  solution  killing  them  readily.  A  very  dilute  kerosene 
emulsion  answers  every  purpose,  and  even  a  weak  salty  solution 
is  satisfactory.  I  have  used  both  kainit  and  muriate  of  potash 
dissolved  in  water  at  the  rate  of  an  ounce  in  a  quart,  and  it  has 
been  perfectly  effective  where  entire  plants  have  been  dipped  into 
it.  A  tobacco  decoction,  one  pound  in  one  gallon  of  water,  is 
also  useful,  and  not  dangerous  to  the  most  delicate  plants.  Where 
house-plants  are  troubled  the  tobacco  water  is  very  convenient, 
or  common  insect-powder  may  be  used  at  the  rate  of  an  ounce 
in  two  quarts  of  water,  and  sprayed  on  with  an  atomizer.  Where 
applications  are  to  be  made  on  a  large  scale,  the  diluted  kerosene 
emulsion  is  the  most  satisfactory,  one  part  in  fifteen  of  water  be- 
ing ordinarily  sufficient. 

Next  comes  a  series  where  the  excretions  are  in  the  form  ot 
waxy  scales,  which  sometimes  become  hard,  brittle,  and  beauti- 
fully ribbed.  The  female  forms  a  sort  of  sac  of  these  waxy  scales, 
and  in  it  the  eggs,  mixed  with  a  very  fine  powder,  are  contained. 
This  type  is  also  rather  more  common  southwardly  or  in  warm 
countries,  the  few  species  that  occur  in  the  North  being  rather 
scarce  and  generally  confined  to  weeds.  The  "  cottony  cushion 
scale,"  Icerya  purchasi,  which  has  caused  such  injury  in  Cali- 
fornia, belongs  here,  and  we  have  several  allied  species  in  Florida, 
and  yet  more  in  the  West  Indies.  All  these  insects  gain  their 
food  by  sucking  the  plant  juices,  and  their  power  of  injury  is 
magnified  by  their  enormous  productiveness. 

Perhaps  this  is  a  good  place  to  speak  somewhat  at  length  on 
this  "  cottony  cushion  scale,"  and  the  measures  taken  against  it 
by  introducing  foreign  predaceous  species.  The  very  remarkable 
success  that  has  attended  the  introduction  of  "lady-birds" 
(Coccinellidae)  from  Australia  has  led  many  persons  to  the  belief 
that  insects  of  similar  character  might  be  introduced  from  other 
countries  to  deal  with  some  of  our  native  species,  and  much 
time  has  been  wasted  and  some  money  spent  by  ill-considered 
schemes  of  this  description.  The  factors  that  caused  success  in 
the  case  of  the  Icerya  were  :   ist,  an  insect  introduced  from  a 


THE    INSECT   WORLD. 


109 


foreign  country  where  it  was  on  the  whole  rather  scarce  and  kept 
in  check  by  natural  enemies  ;  2d,  its  introduction  into  America, 
where  these  natural  enemies  did  not  exist,  and  where  the  insect 
found  favorable  opportunity  for  multiplying  ;  3d,  the  introduction 
of  some  of  its  foreign  parasites  and  of  the  predaceous  insects 


feeding  upon  the  species  ;  lastly,  and  most  important  of  all,  the 
Australian  lady-bird  recognized  no  other  insect  among  those 
found  in  California  as  proper  food,  and  naturally  confined  itself 
entirely  to  these  scales.  The  contest  was  unequal,  and  the  scales 
lost  rapidly,  soon  becoming  nearly  or  quite  exterminated.     The 


AN  ECONOMIC   ENTOMOLOGY. 


Fig 


chances  are  now  that  the  lady-birds  will  follow  them  and  become 
scarce  or  extinct,  unless  they  show  the  power  of  adapting  them- 
selves to  surroundings,  and 
find  other  food  to  their  liking  ; 
but  while  they  have  been  use- 
ful as  against  the  Icerya,  and 
may  have  entirely  destroyed 
it,  we  cannot  hope  that  they 
will  be  equally  successful  in 
coping  with  our  native  insects, 
who  have  long  since  adapted 
themselves  to  their  surround- 
ings in  such  a  way  as  to  make 
it  unlikely  that  any  intro- 
duced species  will  be  effectual 
in  seriously  lessening  their 
numbers.  Insects  of  this  char- 
acter are  susceptible  of  treat- 
ment with  the  kerosene  emul- 
sion, although,  where  they 
occur  in  such  numbers  as  did 
the  Icerya  in  California,  this 
treatment  becomes  exceedingly  expensive  and  practically  useless. 
A  curious  series  of  species  is  found  in  the  genus  Kermes,  often 
found  on  oaks,  and  resembling  at  first  sight  galls  or  even  small 
snail-shells,  their  texture  being  almost  as  brittle  as  if  composed 
of  lime.  They  are  never  economically  important,  but  curious 
enough  to  deserve  mention  here. 

Next  come  what  are  known  as  "soft  scales,"  usually  of  con- 
siderable size  and  readily  visible.  Quite  commonly  they  are 
convex  or  nearly  hemispherical,  rarely  quite  regular  in  outline, 
and  sometimes  ribbed  or  ridged.  In  most  instances  they  are 
brown  in  color,  not  very  rigid  in  texture,  and  easily  crushed  ; 
whence  the  term  "  soft  scales."  We  have  a  number  of  injurious 
species,  and  perhaps  none  more  common  than  the  ' '  cottony 
maple  scale, ' '  Pidvinaria  innumerabilis .  Though  called  the  viaple 
scale,  and  found  most  frequently  on  that  tree,  yet  it  is  by  no 
means  rare  on  grape,  and  often  common  on  the  Virginia  creeper. 
Sometimes  it  occurs  on  other  plants  as  well,  and  is  occasionally 


Icerya  purchasi,  female. 


THE    INSECT   WORLD. 


Ill 


numerous  enough  to  require  treatment.  It  usually  attracts  atten- 
tion in  spring,  when  white  cottony  masses  become  numerous  on 
twigs  or  leaves,  increasing  in  size  until  they  are  one-fourth  of 
an    inch    or    more 

in  length,  and  only  Fic.  83. 

slightly  less  in  diam- 
eter, though  irregu- 
lar in  outline.  The 
mass  seems  cottony, 
but  is  actually  a  wax 
or  gum,  for,  if  a  bit 
is  taken  with  a  for- 
ceps it  can  be  drawn 
out  into  strings  of 
considerable  length. 
When  of  this  size  it 
forms  a  bedding  for 
innumerable,  rusty- 
brown,  minute  eggs, 
which  have  been 
laid  by  the  female 
insect  under  the 
brown  scale  which 
seems  to  form  the 
head  of  the  mass  at- 


Cottony  maple  scale,  Pulvinaria  inniimerabilis,  showing,  at 
a,  the  female  on  a  leaf  and,  at  b,  same  on  a  twig. 


tached  to  the  twig. 

From  these  eggs  minute,  crawling  larvae  hatch,  much  like  the 
,  eggs  in  color,  and  which  separate  in  every  direction  in  what  seems 
to  be  a  moving  mass  of  fine  dust  particles.  In  a  day  or  two  each 
larva  inserts  its  beak  into  a  leaf  or  twig,  and  commences  the  for- 
mation of  a  little,  flattened,  oval,  somewhat  mottled  scale.  They 
remain  thus,  feeding  and  increasing  in  size,  and  as  they  increase 
the  scales  enlarge.  The  males  come  to  maturity  in  the  latter  part 
of  the  summer,  appearing  as  minute,  two-winged  flies,  furnished 
with  long  anal  filaments.  They  mate  with  the  females  which  re- 
main under  the  scale,  and  these,  before  the  leaves  fall,  migrate  to 
the  twigs  or  branches,  where  they  fasten  themselves  to  pass  the 
winter.  Feeding  is  resumed  in  spring,  when  the  sap  begins  to 
circulate,  and  then  the  ^g'g  masses  begin  to  form.     Before  the 


112  AN  ECONOMIC  ENTOMOLOGY. 

cottony  secretion  becomes  visible  the  female  scale  is  less  than 
one-eighth  of  an  inch  in  length,  very  convex,  a  little  irregular, 
and  mahogany-brown  in  color.  As  the  Q^g<g  mass  increases  in 
size  the  scale  is  lifted  posteriorly,  until  finally  the  insect  adheres 
only  by  its  beak  and  by  the  sticky  nature  of  the  cottony  mass. 


Fig 


Cottony  maple  scale. — a,  leaf  covered  with  scales;  b,  male  scale;  c,  adult  male. 

We  have  other  species  of  similar  character  in  which  there  is 
no  cottony  mass  protecting  the  eggs,  but  the  life  history  is  essen- 
tially the  same.  These  ' '  soft  scales' '  mostly  belong  to  the  genus 
Lecanmm,  and  are  much  more  common  southwardly  and  in  con- 
servatories. Citrus  fruits  and  olives  are  especially  subject  to 
soft-scale  attack,  and  the  "black  scale,"  Leca^ihan  olea,  is  in 
California  the  most  troublesome  of  all  and  the  most  injurious. 
In  the  genus  Ceroplastes  the  scale  is  formed  of  waxy  layers, 
sometimes  quite  pretty  in  pattern.  These  are  found  only  in  the 
extreme  South,  and  are  not  especially  troublesome. 

The  matter  of  remedies  will  depend  entirely  upon  circumstances. 
On  garden  plants  or  shrubs  the  scales  may  be  mechanically 
removed  during  the  winter.  They  do  not  adhere  closely,  are 
easily  dislodged,  and  are  of  a  size  sufficient  to  be  readily  seen. 
Not  all,  however,  pass  the  winter  in  the  adult  condition.     In  some 


THE    INSECT   WORLD. 


"3 


cases,  instead  of  a  female,  an  egg  mass  will  be  found  beneath  the 
scale  ;  but  in  either  case  mechanical  dislodging  results  in  the  de- 
struction   of    the     insects. 
Very  often  a  little  judicious  ' 

pruning  or  trimming,  done 
during  the  winter,  will  give 
relief,  because  the  insects 
usually  settle  on  the  termi- 
nal twigs,  and  it  might 
easily  be  that  none  of  the 
larger  branches  contained 
living  scales  or  eggs.  In 
conservatories  the  mechan- 
ical method  is,  all  things 
considered,  the  best.  It 
may  take  a  little  more  time, 
but  it  is  thoroughly  effect- 
ive, and  when  carefully 
done  there  may  be  almost 
total  exemption  until  scales 
are  again  introduced  with 
new  plants. 

This  is  a  good  place  to 
say  that  no  plant  should  be 
placed  in  a  garden  or  con- 
servatory until  it  has  been 
thoroughly  cleaned  of  all 
scales  found  on  twig  or  fo- 
liage, and  a  soft  tooth-  or 

hand-brush,  with  moderately  strong  soapsuds,  forms  a  good  outfit 
for  doing  the  work.  Where  winter  treatment  is  inadvisable  or 
impossible,  applications  should  be  made  when  the  larvae  emerge 
from  the  eggs  and  before  they  fasten  themselves  to  leaves  or 
twigs.  There  is  no  difficulty  in  killing  the  young  with  either 
soapsuds  or  kerosene  emulsion,  but — ^and  here  is  the  important 
point — the  application  must  be  made  before  the  insect  is  pro- 
tected by  a  scale,  or  when  the  scale  is  yet  very  thin  and  newly- 
formed.  Kerosene  will  penetrate  the  waxy  mass  of  the  maple 
scale,  but  it  will  not  certainly  kill  the  eggs  contained  in  it ;  yet 


Lecanium  hemisphericum,  on  orange-leaves,  nat- 
ural size  ;  a,  female  scale,  enlarged. 


114 


AN  ECONOMIC  ENTOMOLOGY. 


if  soapsuds  be  used  to  dilute  the  emulsion,  instead  of  water,  the 
cottony  mass  will  be  so  impregnated  with  soap,  and  become  so 
compact,  that  the  young  will  be  unable  to  make  their  way  out. 
Therefore,  in  this  case,  dilute  three  quarts  of  kerosene  emulsion 
with  one  pound  of  whale-oil  soap  dissolved  in  eight  gallons  of 
water. 

The  most  troublesome  of  all  scale  insects  belong  to  the  Dia- 
spince,  or  * '  armored  scales, ' '  and  these  are  generally  small  in 
size.  They  are,  as  a  rule,  only  a  little  convex,  occasionally  even 
flattened,  and  in  texture  are  more  like  membrane  or  parchment 
than  wax.  All  kinds  of  shapes  occur,  and  there  is  considerable 
variation  in  life  history.  In  one  point  they  all  agree, — after  the 
active  larvae  have  once  become  fixed  and  covered  with  a  scale, 
they  never  leave  their  position,  except  when  the  males  emerge 
as  adults  and  visit  the  surrounding  females.  In  general  the  life 
history  of  the  insects  is  as  follows  :  the  larvae,  whether  hatched 
from  the  eggs  or  born  alive,  crawl  about  for  a  few  hours,  or  at 
most  a  day  or  two,  seeking  a  convenient  place  to  fix.  They  are 
always  minute,  flattened,  oval  creatures,  with  six  legs,  a  pair  of 
distinct  feelers,  and  a  curious,  long,  sucking  mouth.  This  is 
soon  inserted  into  the  plant  tissue,  and  from  that  time  the  insect 
is  a  fixture.  Little  waxy  filaments  begin  to  exude  from  the  body, 
which  soon  coalesce,  or  run  together,  forming  a  first  covering  or 
scale  over  the  soft  larva.  The  insect  soon  moults,  and  the  cast 
skin  forms  part  of  the  scale,  the  resulting  creature  being  legless 
and  without  power  of  motion.  There  is  one  additional  moult, 
after  which  the  sexes  are  very  different  in  appearance.  The  male 
shows  antennae,  legs,  and  wings  well  marked,  and  is  indeed  a 
perfect  pupa,  while  the  female  is  even  more  grub-like  than  before, 
rudiments  of  antennae  only  being  visible.  The  second  cast  skin 
of  the  female  also  forms  a  part  of  her  scale,  and  there  is  nearly 
always  some  difference  in  shape  between  the  sexes,  the  male 
being  not  only  smaller,  but  narrower.  Shortly  after  the  change 
to  the  pupa  the  male  becomes  adult,  and  in  this  series  has  the 
end  of  the  abdomen  prolonged  into  a  style  or  pointed  process, 
sometimes  equalling  in  length  the  rest  of  the  insect,  though 
usually  shorter.  Antennae  and  wings  are  both  prominent,  and 
as  a  whole  the  insect  is  curious  and  exceedingly  fragile  in  appear- 
ance.    Its  life  is  probably  short,  though  long  enough  to  accom- 


THE    INSECT   WORLD. 


"5 


plish  its  mission, — the  fertilization  of  the  female.  After  this  the 
life  histories  differ  greatly  ;  sometimes  the  female  lives  through 
the  winter  in  the  partly-grown  or  adult  condition  ;  sometimes  she 
lays  eggs  which  fill  up  the  entire  space  beneath  the  scale,  the 
insect  itself  shrivelling  up  until  scarcely  a  trace  remains.  Some- 
times living  young  are  brought  forth,  and  there  may  be  one  or 
several  broods.  Hence  it  is  necessary  to  study  each  species  in 
detail  before  we  can  say  much  on  the  subject  of  remedies.  It  is 
obviously  beyond  the  province  of  this  book  to  describe  all  the 
injurious  species,  and  general  statements  only  are  possible. 

Fig.  86. 


Oyster-shell  scale,  M\tila'if<is  pomoriDii. — a,  female  scale,  from  beneath,  filled  with 
eggs ;  b,  same,  from  above  ;  c,  twig  infested  by  female  scales  ;  d,  male  scale  and  a  twig 
infested  therewith. 

Perhaps  the  most  common  forms  of  this  series  are  the  ' '  oyster- 
shell'  '  bark-lice,  of  which  we  have  several  species,  deriving  their 
common  name  from  the  fact  that  the  scales  have  a  marked  resem- 
blance to  the  shells  of  some  oysters.  In  the  Northern  United 
States  Mytilaspis  pomorum  is  the  common  form,  infesting  apple 


ii6 


AN  ECONOMIC  ENTOMOLOGY. 


and  other  fruit  trees,  willow,  lilac,  and  a  great  variety  of  other 
plants.  It  is  perhaps  uncertain  whether  all  are  really  one  species, 
but  for  our  present  purpose  we  may  consider  them  so.  There  is 
one  brood  only,  and  they  winter  in  the  &^%  state,  the  larvae 
appearing  in  spring,  the  time  depending  upon  the  weather.  In 
the  South  there  may  be  two  broods,  but  I  believe  that  there  are 
few  exceptions  to  the  rule  that  wintering  takes  place  in  the  ^^^ 
stage.  On  orange  and  other  citrus  plants  we  have  species  closely 
resembling  that  on  the  apple,  and  not  distinguishable  except  on 

Fig.  87. 


Mytilaspis  pomorum.—a,  male  ;  b,  its  tarsus  ;  c,  young  larva  ;  rf,  its  antenna  ;  c,  female. 

close  examination,  even  by  the  specialist.  These  scales  some- 
times cover  twigs  and  large  branches  completely  ;  even  the  leaves 
are  often  infested,  and  not  infrequently  the  fruit  itself  becomes 
more  or  less  covered.  It  is  not  unusual  to  see  in  market  oranges 
and  lemons  more  or  less  spotted  by  these  oyster-shell  scales,  and 
I  have  seen  lemons  from  Mediterranean  countries  with  the  skin 
almost  entirely  hidden  by  them. 


THE    IXSECT   WORLD. 
Fig.  88. 


117 


-^^^^^EEQCT 


The  San  Jose  scale  :  winded  male  above  ;  a,  young  larva,  just  hatched  ;  b,  its  antenna ; 
c,  female,  showing  the  forming  young  through  the  body  wall ;  d,  outline  of  anal  plate 
of  female  :  all  very  much  enlarged. 


Ii8  AN  ECONOMIC  ENTOMOLOGY. 

In  our  treatment  of  these  insects  we  must  either  apply  exceed- 
ingly caustic  winter  washes,  to  corrode  the  scale  and  allow  the 
eggs  to  be  washed  out  by  rain  or  destroyed  by  other  climatic 
influences,  or  we  must  apply  contact  insecticides  when  the  eggs 
hatch  or  the  larvae  emerge  from  beneath  the  scales. 

Some  of  our  destructive  species  belong  to  the  genus  Aspidiotus, 
and  these  have  the  scale  nearly  circular  in  outline,  with  the  rem- 
nants of  the  cast  larval  skins  showing  through  at  or  near  the 
middle  and  forming  a  sort  of  nipple-like  prominence.  The  male 
scales  are  decidedly  smaller  than  those  of  the  female,  and  some- 
what more  oval  or  oblong.  The  ' '  red  scales' '  of  the  orange  in 
California  and  in  Florida  belong  to  this  genus  ;  but  perhaps  the 
most  troublesome  of  all  is  the  A.  per^iiciosus ,  or  San  Jos^  scale. 
As  this  species  is  now  widely  distributed  and  very  injurious  where 
it  occurs,  its  life  history  may  be  given  in  some  detail. 

The  insect  winters  on  the  infested  trees  in  the  larval  state,  and 
usually  about  half  grown,  both  sexes  being  found.  Males  mature 
soon  after  spring  opens, — in  the  latitude  of  Philadelphia,  about 
the  end  of  May,  but  depending  somewhat  upon  the  season. 
On  or  about  the  loth  of  June  the  females  become  fully  devel- 
oped, and  begin  to  bring  forth  living  young.  That  is  to  say,  the 
species  is  viviparous,  and  produces  no  eggs.  The  larvae  do  not 
differ  essentially  from  those  of  other  scales,  and  fix  in  from  twelve 
to  thirty-six  hours,  depending  somewhat  upon  circumstances. 
At  that  time  a  thin  white  pellicle  forms,  which  soon  turns  yellow, 
and  a  little  later  becomes  gray  around  the  edges.  The  insect  is 
then  a  fixture,  and  continues  its  growth  much  as  previously 
described,  but  reaches  the  adult  condition,  and  is  ready  to  repro- 
duce, in  a  little  more  than  a  month.  This  short  period  enables 
it  to  mature  several  broods,  and  during  the  entire  summer,  and 
until  late  fall,  reproduction  continues, — the  broods  becoming 
mixed,  and  all  stages  being  present  continuously  upon  the  plants 
soon  after  summer  opens.  With  such  a  life  history  the  insect  is 
exceedingly  difihcult  to  control,  and  practically  we  are  reduced  to 
winter  work,  as  will  be  hereafter  pointed  out.  The  scale  infests 
all  the  usual  deciduous  fruit-trees,  roses,  currants,  gooseberries, 
— in  fact  the  entire  order  Rosacece,  and  occasionally  occurs  on 
chestnut,  walnut,  and  elm.  It  is  probable  that  yet  other  plants 
are  subject  to   infestation,  and  this  omnivorous  habit  and  the 


THE    INSECT   WORLD. 


119 


\ 


wonderful  power  of  reproduction  make  the  scale  especially  dan- 
gerous. 

In  the  genus  Diaspis  tiie  scales  are  more  oval,  and  the  cast 
larval  skins  are  at  or  near  the  margin  rather  than  toward  the 
middle,     while    the 

males  are  long  and  Fig.  89. 

slender.  A  common 
example  is  the  Di- 
aspis rosa;,  found 
on  roses  and  other 
plants  belonging  to 
the  same  natural 
family.  The  scale 
is  pure  white  and 
very  conspicuous, 
measuring  nearly  an 
eighth  of  an  inch  in 
diameter. 

Yet  more  oval, 
with  the  cast  larval 
skins  at  the  smaller 
extremity,  are  spe- 
cies of  Chioiiaspis, 
and  a  good  exam- 
ple is  the  ' '  scurfy 
scale, ' '  C.  furfu- 
rus,  common  on 
pear  and  apple.  A 
similar  species  is 
found  on  pine  and 
spruce     throughout 

the  United  States.     These  species  may  have  one  or  two  gener- 
ations, according  to  latitudes,  but  ususally  winter  in  the  egg  state. 

Some  of  the  species  have  the  curious  habit  of  boring  under 
bark,  thus  passing  a  large  part  of  their  life  out  of  sight,  becoming 
more  dangerous  by  that  fact,  since  trees  may  be  badly  infested 
and  the  cause  of  sickness  not  even  suspected  by  the  farmer. 

It  is  practically  impossible  to  even  mention  all  the  injurious 
scales  of  house,   conservatory,  or  orchard  plants,  and  it  is  not 


/ 


CL 

San  Jose  scale  on  a  California  pear,  natural  size  ;  the  scale 
itself  enlarged  at  b. 


AN  ECONOMIC  ENTOMOLOGY. 


really  necessary,  since  the  treatment  to  be  adopted  is  nearly  the 
same  in  all  cases.  On  deciduous  trees,  where  the  scales  remain 
during  the  winter  upon  trunks  and  branches,  and  where  the  trees 
become  dormant,  the  scales  are  best  treated  during  the  winter. 
At  that  time  there  is  no  foliage  to  interfere,  and  we  can  use  much 
stronger  washes  than  would  be  safe  during  the  summer,  or  when 
the  tree  is  active.  I  have  already  called  attention  to  the  fact  that 
it  is  difficult  to  penetrate  insect  tissues  with  ordinary  liquids,  and 
it  has  been  found  impossible  in  practice  to  obtain  good  results  in 
the   destruction   of  scale  insects  except   by  means  of  caustics. 

Potash    and    soda    have 
Fig.  90.  been  used  with  good  effect 

even  in  a  simple  watery 
mixture,  but  more  satis- 
factorily in  the  form  of 
very  caustic  soap.  Whale, 
or  other  fish-oil  soap,  at 
the  rate  of  two  pounds  in 
one  gallon  of  water,  as  a 
winter  wash,  has  proved 
absolutely  effective  against 
the  San  Jos6  scale  and  the 
oyster-shell  bark-louse, 
two  of  the  most  resistant 
of  the  armored  scales. 
The  simple  muriate  of 
potash  used  as  a  fertil- 
izer has  proved  effective 
against  the  scurfy  scale,  while  common  laundry  soap  has  been 
efficient  against  others  of  the  softer  species.  The  common  soaps 
are  all  caustic,  and,  when  applied  at  the  strength  indicated,  the 
scale  is  shrivelled,  lifted,  and  partially  corroded,  so  that  the  oily 
mixture  works  its  way  beneath,  into  absolute  contact  with  the 
insect.  Or  it  is  raised  at  the  edges  and  washed  off  by  the  rains, 
carrying  with  it  either  eggs  or  young,  as  the  case  may  be.  In 
fact,  where  the  eggs  hibernate  winter  applications  act  only  by 
exposing  them,  so  that  they  are  easily  washed  away  by  rains  and 
scattered,  under  no  proper  condition  to  hatch.  Or,  should  they 
hatch,  the  larvae  are  able  in  rare  instances  only  to  get  upon  the 


3 

The  scurfy  scale,  Chionaspis  furfurus. — a,  twig 
infested  by  female  scales  ;  b,  with  male  scales  ;  c, 
female  ;  d,  male  scale,  much  enlarged. 


THE   INSECT   WORLD.  121 

proper  food-plant.  In  the  case  of  plants  which  do  not  lose  their 
foliage  at  any  period,  or  in  conservatories,  or  where  winter  treat- 
ment for  any  reason  is  not  feasible,  we  must  attack  the  insects 
when  the  larvae  are  crawling  about,  and  before  they  are  fixed. 
At  that  time,  while  not  protected  by  a  scale,  they  may  be  easily 
killed,  almost  any  of  the  contact  insecticides  being  effective. 
Soapsuds,  a  dilute  kerosene  emulsion,  or  a  mixture  of  both,  are 
satisfactory,  and  a  good  formula  is  :  kerosene  emulsion  one  part, 
soapsuds  ten  parts,  the  suds  being  of  the  strength  of  one  pound 
of  soap  to  six  gallons  of  water.  Whale  or  other  fish-oil  soap  is 
better  than  common  laundry  soap,  and  the  latter  is  better  than 
high-grade  articles  containing  only  a  minimum  amount  of  caustic. 
This  would  not  hurt  any  except  very  delicate  plants,  while  it 
would  be  absolute  death  to  larval  scales.  It  is  useful  in  the  con- 
servatory on  palms,  which  are  often  much  infested,  and  for  some 
of  these  it  might  be  well  to  reduce  the  amount  of  kerosene  to 
one  part  of  the  emulsion  with  from  twelve  to  fifteen  parts  of  soap- 
suds. Where  the  insects  are  viviparous,  or  bring  forth  Uving 
young,  the  spraying  must  be  done  systematically,  at  intervals  of 
four  or  five  days,  until  no  more  young  appear.  On  out-door 
plants  the  same  mixture  may  be  used,  but  the  spraying,  if  the 
larvae  come  from  eggs,  need  not  be  done  more  than  twice,  since 
as  a  rule  the  eggs  hatch  at  about  the  same  time.  On  the  Pacific 
Coast  lime,  salt,  and  sulphur  mixtures,  and  various  resin  washes, 
have  proved  effective,  but  they  are  troublesome  to  make,  and 
hardly  cheaper,  all  things  considered,  than  the  soap  mixtures 
above  referred  to.  They  act  largely  by  sealing  the  scales  to  the 
tree,  so  that  the  young  cannot  emerge  or  the  adults  are  stifled  ; 
hence  they  are  most  effective  where  rains  are  few  and  far  between. 
The  formulae  for  their  preparation  will  be  found  in  the  chapter  on 
insecticides,  where  their  range  of  usefulness  is  also  stated. 

The  species  belonging  to  the  family  AleyrodidcB  resemble 
scale  insects  in  the  immature  condition,  but  are  not  fixed  to  the 
plants,  and  in  the  adult  stage  both  sexes  are  winged,  somewhat 
resembling  minute  plant-lice.  The  striking  character  by  which 
they  may  always  be  recognized  is  a  covering  of  white,  flour-like 
powder,  which  renders  them  easily  visible  upon  the  leaves. 
They  are  not  common  on  out- door  crops  in  the  North,  but  are 
not  infrequent  on  house  or  conservatory  plants,  becoming  more 


122  AN  ECONOMIC  ENTOMOLOGY. 

abundant  and  correspondingly  more  troublesome  southward.  A 
species  sometimes  occurs  in  considerable  number  on  orange.  As 
the  insects  live  exposed  in  all  stages,  they  are  easily  reached  by 
contact  poisons,  and  of  these  the  kerosene  emulsion  is  usually  the 
most  satisfactory.     It  kills  them  in  all  stages  at  moderate  strength. 


one  part  of  emulsion  in  ten  or  twelve  parts  of  water  being  ordi- 
narily sufficient.  Whale-oil  soap  is  quite  as  effective,  and  is 
preferable  on  some  house  or  conservatory  plants,  while  even  the 
pyrethrum  extract  is  useful  on  a  small  scale,  and  is,  perhaps,  the 
cleanest  of  all  on  house-plants. 


THE    INSECT   WORLD. 


123 


It  is  a  short  step  from  the  Aleyrodid^  to  the  plant-lice,  be- 
longing to  the  family  Aphididce.  Plant-lice  are  well  known  to 
agriculturists  by  the  injury  they  cause,  and  they  are  interesting 
to  the  naturalist  from  their  life  history.  Here  we  have  the  most 
striking  apparent  exception  to  the  general  rule  that  insects  are 
developed  from  eggs,  and  yet  perhaps  the  exception  is  more 
apparent  than  real.  At  all  events,  parthenogenesis,  or  repro- 
duction without  the  intervention  of  a  male,  occurs  normally  in  a 
large  percentage  of  the  species.  Of  course  there  are  many  differ- 
ences in  life  habits,  but  a  general  account,  covering  most  of  the 
cases,  is  all  that  can  be  attempted  here.     As  a  rule,  plant-lice 

Fig.  92. 


a,  female   hop-louse,  showing  eggs  through  skin  ;    b,  the  stem-mother  that  starts  the 
transformation  ;  much  enlarged. 


winter  in  the  &^%  stage  ;  but  this  is  subject  to  many  exceptions, 
especially  in  the  warmer  parts  of  the  country.  Early  in  spring, 
as  soon  as  there  is  a  trace  of  reviving  vegetation,  these  eggs 
hatch.  The  insect  that  now  appears  is  wingless,  and  usually 
remains  so,  but  grows  rapidly  by  sucking  the  plant  juices,  and 
soon  begins  to  produce  living  young.  It  is  called  a  "stem- 
mother,"  because  it  is  the  source  from  which  numerous  genera- 
tions issUe  during  the  season.  All  the  young  born  by  this  stem- 
mother  are,  like  herself,  without  sex  ;  that  is,  they  are  neither 
males  nor  sexually-developed  females.  The  rate  at  which  they 
are  born  varies,  but  as  many  as  eight  living  young  have  been 


124 


AN  ECONOMIC   ENTOMOLOGY. 


observed  within  a  period  of  twenty-four  hours  from  one  specimen, 
and  it  is  not  unusual  to  find,  early  in  the  season,  a  single  large 
louse  surrounded  by  a  group  of  anywhere  from  a  dozen  to 
twenty  or  even  more  small  specimens.  The  rate  of  growth  also 
varies,  depending  upon  the  weather  ;  indeed  weather  conditions, 
early  in  the  season,  frequently  determine  the  question  of  whether 
or  not  certain  species  are  to  become  injurious  later  on.  A  warm, 
moist  temperature  favors  their  development,  and  reproduction 
goes  on  at  a  rapid  rate.  Correspondingly,  cold,  wet  weather 
checks  development,  and  may  even  destroy  a  large  number, 
especially  of  the  young.  Plant-lice,  in  their  younger  stages,  are 
exceedingly  susceptible  to  sudden  changes  of  temperature,  and 
at  almost  any  time  in  the  season  a  sudden  drop  of  from  fifteen  to 
twenty  degrees,  accompanied  by  a  rain,  will  prove  fatal  to  a  great 
proportion  of  them.  But  assuming  that  all  is  favorable,  the 
young  that  were  first  brought  forth  are  in  turn  ready  to  repro- 
duce in  five  or  six  days,  and  they  also  form  little  colonies  ;  this 
method  of  reproduction  continuing  as  long  as  food  is  plenty  and 
the  weather  mild.  Experimentally,  reproduction  of  this  kind 
has  been  continued  for  several  years  in  succession,  without  any 
tendency  to  develop  sexed  individuals  or  to  produce  eggs.  At 
almost  any  time  after  the  first  generation,  specimens  may  become 
winged,  and  these  fly  to  other  localities,  forming  new  colonies 
wherever  suitable  food  is  found.  In  this  way  they  spread,  and, 
though  they  may  have  started  from  a  single  favorable  locality, 
yet  in  the  course  of  a  few  weeks  they  may  cover  many  hundreds 
of  acres.  Exactly  what  determines  the  formation  of  wings  in 
some  specimens  and  not  in  others  is  not  known.  We  do  know, 
however,  that  the  progeny  of  a  single  individual  is  variable,  and 
that  while  some  become  winged  others  do  not ;  but  whether 
winged  or  wingless,  the  specimens  are  equally  without  sex,  and 
all  are  viviparous,  or  bring  forth  living  young.  As  the  summer 
advances,  reproduction  becomes  less  rapid.  Plants  tend  to  dry, 
the  supply  of  sap  is  not  so  plenty,  and  these  features  become 
more  marked  through  the  autumn  months  until,  with  the  ap- 
proach of  cold  weather,  plant  growth  entirely  ceases.  It  becomes 
necessary  now  to  provide  for  the  continuation  of  the  species 
during  winter,  and  sexed  forms  are  developed.  The  males  are 
usually  winged  and  appear  a  short  time  before  the  females,  which 


THE   INSECT   WORLD. 


125 


differ  by  the  lack  of  wings  and  the  usually  small  size  compared 
with  the  normal  sexless  form.  Pairing  takes  place  as  soon  as 
the  female  is  sexually  mature,  and  in  a  very  few  days  after- 
wards eggs  are  laid.  In  many  instances  the  o^g^  supply  is 
exceedingly  small,  indeed  there  may  be  one  only  matured  by 
a  female.  Even  this  may  remain  within  the  body  of  the  parent, 
who  simply  dries  up,  the  skin  shrivelling  around  and  form- 
ing a  protection  to  the  ovum.  More  usually  several  eggs  are 
produced,  and  these  of  large  size  in  proportion  to  the  size  of 
the  insect  that  lays  them.     They  are  green  or  greenish-brown 

Fig.  93. 


Hop-louse,  male;  return  migrant. 


in  color  when  laid,  sometimes  yellowish,  and  frequently  darken 
to  black.  They  are  placed  in  sheltered  situations  on  plants,  and, 
in  the  case  of  orchard  trees,  are  usually  found  at  the  tips  of  twigs, 
around  the  buds,  or  on  the  leaf-scales,  where  vegetation  will  first 
start  in  the  spring  following.  They  are  very  firm  in  texture  and 
very  resistant  to  insecticides  ;  in  fact,  it  is  impossible  to  destroy 
them  except  by  the  most  caustic  mixtures.  It  has  been  already 
indicated  that  there  are  many  exceptions  to  this  general  life  his- 
tory, and  one  kind  of  exception  we  find  where  species  feed  dur- 


126  AN  ECONOMIC   ENTOMOLOGY. 

ing  the  summer  upon  a  plant  which  dies  down  to  the  ground, 
leaving  nothing  through  the  winter.  In  such  cases  there  is  an 
alternate  food-plant,  upon  which  the  winter  and  early  spring  are 
passed.  From  this  the  insects  migrate  in  early  summer  and  to 
it  they  return  when  cold  weather  sets  in.  Such  a  case  we  have 
in  the  hop-louse,  which  spends  the  summer  upon  the  hop,  in- 
creasing greatly  in  number  in  favorable  seasons  and  often  causing 
much  injury.  When  the  vines  mature  and  die,  males  develop, 
and  all  the  lice  fly  to  plum-trees.  Here  the  female  is  born,  the 
sexes  mate,  and  eggs  are  laid.  In  the  spring  two  or  more  gen- 
erations mature  upon  the  plum,  and,  when  the  vines  are  again 
well  started,  winged  forms  develop  and  migrate  to  their  summer 
food-plant.  This  sort  of  migration  is  not  unusual,  although  it 
has  not  been  traced  out  in  many  cases. 

Another  example  we  find  in  the  "melon-louse,"  which  has  a 
considerable  range  of  food-plants,  including  cotton,  orange, 
strawberry,  and  nearly  all  the  common  weeds  of  our  fields.  If 
circumstances  favor  their  increase  in  spring,  winged  forms  are 
produced  which  migrate  and  settle  upon  melon  fields,  providing 
for  colonies  during  the  summer. 

The  scientific  problems  connected  with  this  method  of  repro- 
duction and  spread  are  of  great  interest,  but  cannot  be  entered 
upon  here  ;  the  mere  statement  of  the  case  being  sufficient  for 
practical  purposes.  Plant-lice  are  so  commonly  known  that  a 
detailed  description  of  their  appearance  is  unnecessary  ;  but  it  is 
well  to  call  attention  to  the  presence  of  a  pair  of  little  tubes  or 
cornicles  near  the  end  of  the  abdomen,  projecting  from  the  upper 
surface.  These  are  called  honey-tubes,  and  from  them  is  excreted 
a  sweetish  liquid  known  as  honey-dew.  Sometimes,  when  food 
is  abundant  and  the  insects  are  active,  the  amount  of  sap  they 
pump  out  of  the  plants  is  so  great  that,  in  order  to  ease  them- 
selves, they  void  it  in  little  streams  through  the  anus,  as  well  as 
in  drops  through  the  honey-tubes.  Thus  the  leaves  of  infested 
plants  become  sticky  or  glazed  with  a  sweetish  liquid,  on  which 
a  black  fungus  rapidly  develops,  the  leaf  being  frequently  killed 
by  simply  choking  to  death.  Sometimes  the  vegetation  beneath 
a  tree  becomes  thoroughly  coated  in  the  same  way,  or,  when 
shade-trees  in  cities  are  infested,  the  pavement  becomes  wet  and 
slippery  with  the  viscid  liquid.     This  honey-dew  is  often  attractive 


TilE    INSECT   WORLD.  1 27 

to  bees  and  wasps,  who  feed  greedily  upon  it,  and  is  yet  more 
tempting  to  ants,  whose  relations  to  plant-lice  merit  more  than  a 
passing  notice,  since  they  are  of  decided  economic  importance. 

It  is  a  common  thing  to  see  ants  crawling  over  leaves  infested 
by  plant-lice,  and  it  is  often  considered  well  that  this  should  be 
so,  under  the  erroneous  impression  that  the  ants  feed  upon  plant- 
lice.  In  some  cultivated  fields  ant-hills  abound  early  in  spring, 
the  little  mounds  scarcely  rising  above  the  surface,  being  seen 
everywhere.  We  next  find,  shortly  after,  plant-lice  infesting  the 
roots  or  leaves  of  the  growing  crop.  In  truth,  ants  are  protectors 
of  plant-lice  ;  they  are  fond  of  their  sweet  excretion,  and  favor 
their  increase  and  development  in  every  possible  way.  The 
plant-lice  seem  to  realize  that  they  have  nothing  to  fear,  and 
readily  yield  to  the  ants  of  their  sweets  whenever  approached  for 
that  purpose.  Some  species  of  aphids  are  indeed  practically 
dependent  upon  ants  for  their  existence.  Where  some  of  them 
lay  their  eggs  we  have  not  yet  been  able  to  learn,  but  perhaps 
they  simply  drop  them  to  the  ground,  where  their  color  and  size 
render  them  invisible  to  our  eyes.  The  ants  find,  gather,  and 
carry  them  into  their  galleries,  where  they  store  them  until  spring. 
When  vegetation  starts  and  all  conditions  are  favorable,  the 
eggs  are  taken  where  they  can  hatch  normally,  the  young  lice 
being  afterward  carried  to  the  plants  upon  which  they  are  to  feed. 
An  instance  nearly  like  this,  save  that  the  young  are  carried  over 
winter,  we  find  in  the  lice  infesting  corn  roots,  and  undoubtedly 
there  are  many  others. 

The  study  of  plant-lice  is  difficult  by  reason  of  the  matters 
already  set  out,  and  it  sometimes  requires  years  to  supply  a  miss- 
ing link  in  their  life  history.  The  differences  between  tbem  are 
not  always  well  marked,  and  the  tendency  has  been  to  recognize 
species  as  distinct  when  they  feed  on  different  food-plants.  This 
basis  has  proved  erroneous,  however,  and  now  the  wonder  is  to 
find  how  many  food-plants  a  single  species  may  actually  have. 

It  has  been  mentioned  that  a  number  of  plant-lice  feed  upon 
roots,  and  some  species  pass  their  entire  life  underground.  Such 
are  the  Rhizobiince ^  which  sometimes  become  distinctly  injurious, 
as,  for  instance,  when  they  occur  on  the  roots  of  lettuce,  in  green- 
houses and  out-doors.  Sometimes  they  are  found  on  the  roots 
of  trees  or  shrubs,  quite  usually  attended  by  ants,  which  provide 


128 


AN  ECONOMIC  ENTOMOLOGY. 


for  their  distribution.  As  they  never  come  to  the  surface,  so  far 
as  we  know,  they  are  never  winged,  and  are  usually  dull  white 
in  color,  or  with  a  slight  tinge  of  green.  The  body  is  covered 
with  a  whitish  powder  and  lacks  honey-tubes. 

Fig.  94. 


Phylloxera  vastatrix.—a.  unaffected  rootlet  of  grape ;  b,  rootlets  with  newly-formed 
galls;  c,  same,  with  old  and  dried-up  tissue;  dd,  groups  of  the  lice  on  roots  and  root- 
lets ;  e,f,  female  pupa,  from  above  and  below;  g,  h,  winged  females;  i,  an  antenna;  j, 
oviparous  wingless  female  and  her  eggs;  k,  root  showing  location  of  the  eggs. 

An  advance  upon  those  root-living  species  is  found  in  Phyl- 
loxera, which  belongs  with  Chermes  in  a  sub-family,  Chermesiiia, 


THE    LWSECT    WORLD.  129 

distinguished  by  having  only  two  discoidal  veins  on  the  fore- 
wings.  The  grape  Phylloxera  is  known  by  reputation  all  over 
the  world,  and  its  ravages  in  European  countries  have  called 
forth  volumes  of  print.  It  has  been  thoroughly  studied  in  our 
own  country  by  Dr.  C.  V.  Riley,  among  others,  and  from  his 
works  the  following  life  history  is  taken. 

The  insect  winters  on  the  roots  of  grape,  mostly  as  a  young 
wingless  form.  This  starts  growth  in  spring,  rapidly  increases 
in  size,  and  soon  commences  to  lay  eggs,  the  young  from  which, 
like  their  mothers,  remain  wingless,  are  also  sexless,  and  also  lay 
eggs  ;  and  so  we  may  have  a  series  of  generations  of  similar 
creatures,  no  true  sexes  becoming  developed,  no  wings  appear- 
ing, and  reproduction  being  entirely  through  unfertilized  eggs. 
Sometimes,  in  midsummer,  some  individuals  acquire  wings,  and 
thus  we  get  migrating  forms,  which  issue  from  the  ground  while 
yet  in  the  pupa  stage,  and,  as  soon  as  they  become  winged,  fly 
and  spread  to  other  vineyards  in  the  vicinity.  Eggs  are  then 
laid,  usually  on  the  under  side  of  the  leaves,  from  three  to  eight 
being  the  range,  while  five  is  perhaps  the  usual  number.  They 
are  of  two  sizes,  of  which  the  larger  produce  females,  the  others 
males,  and  they  come  from  the  eggs  fully  developed  and  ready 
to  reproduce.  These  curious  creatures  have  become  modified 
for  the  one  purpose  of  reproducing  their  kind,  and  can  neither 
feed,  for  the  mouth  is  aborted,  nor  fly,  for  they  have  no  wings. 
After  copulation  a  single  ^%%,  almost  as  large  as  the  insect  itself, 
is  developed  in  the  female,  and  from  it  hatches  a  form  which  is 
like  the  type  which  started  the  cycle  early  in  the  season.  Curi- 
ously enough,  it  occasionally  happens  that  some  of  the  wingless 
forms  which  remain  underground  also  lay  eggs  of  two  different 
sizes,  producing  males  and  females,  and  thus  it  appears  that 
winged  forms  are  not  really  necessary  to  the  continuation  of  the 
species.  Quite  usually  wingless  individuals  abandon  the  roots 
and  crawl  up  the  stems  to  the  leaves,  where  they  form  the  galls, 
which  are  the  most  prominent  external  indications  that  a  vine 
is  infested.  I  have  seen  vineyards  in  New  York  and  New  Jersey 
in  which  almost  every  leaf  showed  these  galls,  yet  withal  no  real 
injury  had  been  done.  In  other  words,  most  of  the  native 
American  vines  are  able  to  sustain  the  attack  of  the  species. 
This  is  not  true  of  the  vines  in  Europe,  where  this  insect  has 

9 


I30 


AN   ECONOMIC  ENTOMOLOGY. 


been  introduced,  and,  after  a  long  series  of  experiments  with 
insecticides,  none  of  which  proved  satisfactory,  resort  was  finally- 
had  to  American  stocks  upon  which  the  foreign  varieties  were 
grafted.  This  has  proved  effectual  to  an  extent ;  but  it  seems 
that,  in  the  course  of  time,  the  period  varying  somewhat,  even 

American   stocks  lose 
^^^-  ^^-  their      exemption     in 

Europe  and  become 
gradually  subject  to 
injury  from  the  Phyl- 
loxera attacks. 

We  have  a  number 
of  species  of  this  same 
genus  infesting  a  great 
variety  of  plants  not 
of  economic  interest. 
Perhaps  the  most  com- 
mon is  that  which 
forms  large,  blister- 
like galls  on  hickory 
leaves,  so  prominent 
as  to  attract  attention 
from  even  the  most 
casual  observer.  If  one  of  these  galls  be  cut  open,  the  inside 
will  be  found  lined  with  numerous  minute,  yellow  insects,  with 
dusky  wings  which  lie  folded  flat  over  the  back,  and  in  this  par- 
ticular the  Phylloxera  differs  from  the  typical  aphids,  which  have 
the  wings  vertical  when  at  rest. 

The  subject  of  dealing  with  underground  pests,  or  plant-lice 
which  feed  upon  roots,  is  one  of  importance,  upon  which  the 
last  word  has  not  yet  been  said.  As  against  the  Phylloxera, 
bisulphide  of  carbon  has  proved  useful,  injected  by  means  of  a 
proper  instrument  into  the  ground  at  about  the  level  of  the  roots 
and  allowed  to  permeate  the  soil.  The  fumes  are  deadly  to 
insects,  and  where  they  reach  them  in  any  but  the  &^^  stage, 
kill.  The  Phylloxera  does  not  require  attention  in  our  country 
at  the  present  time,  and  no  large  space  need  be  given  the  subject 
of  remedies  against  it.  The  matter  is  different  when  we  consider 
the  species  which  infest  other  cultivated  plants  ;  whether  Rhizo- 


Galls  of  Phyllo.xera  on  grape-leaf. 


THE    INSECT    IVORLD. 


131 


biini,  or  forms  like  the  "peach-louse"  or  the  '"woolly  apple- 
louse,"  where  they  may  be  on  leaves,  twigs,  and  roots  at  one  or 
different  times.  Bisulphide  of  carbon  can  be  used  with  good 
effect  in  such  cases  ;  but  it  is  rather  an  expensive  application, and 
there  is  an  element  of  danger  that  makes  it  desirable  to  employ 
something  equally  effective  yet  less  liable  to  injure  vegetation. 
Very  satisfactory  results  have  been  obtained  with  tobacco,  some 
under  my  own  observations,  some  reported  by  other  trained 
observers,  and  it  seems  fairly  well  proved  that  trenching  around 
an  infested  tree,  and  filling  into  the  trench  a  liberal  supply  of 
ground  tobacco,  refilling  the  trench  immediately  after,  will  have 
the  effect  of  clearing  the  roots  of  these  pests.  This  has  been 
used  more  particularly  against  the  peach  aphids,  and  has  been 
almost  uniformly  successful.  Tobacco  is  a  good  fertilizer,  and 
many  dealers  carry  the  coarsely  ground  product  as  part  of  tiieir 
stock  in  trade.  It  is  rather  expensive  as  a  fertilizer,  but  cheap  as 
an  insecticide,  and  a  double  value  is  obtained  because  besides 
killing  the  lice  it  also  stimulates  the  trees  or  other  plants.  The 
use  of  tobacco,  therefore,  where  root-lice  are  troublesome,  is 
good  farm  practice.  It  may  be  well  to  say,  however,  that  little 
or  no  benefit  is  derived  from  the  use  of  stems  spread  upon  the 
surface,  or  dug  in,  because  there  is  not  a  sufficiently  rapid  extrac- 
tion of  the  nicotine,  and  this  is,  after  all,  the  killing  agent.  The 
ground  material  on  the  other  hand  gives  up  its  nicotine  readily 
to  a  small  quantity  of  moisture,  and  it  will  be  quickly  carried 
down  and  around  the  roots  of  the  plants,  into  direct  contact  with 
the  insects.  In  land  infested  by  root-lice  the  use  of  commer- 
cial fertilizers  is  indicated.  It  has  been  found  by  experience  that 
salty  mixtures  kill  plant-lice  more  or  less  rapidly,  and  therefore, 
where  root-lice  are  present,  potash  in  the  form  of  kainit  and 
nitrogen  in  the  form  of  nitrate  of  soda  are  advisable.  I  have 
frequently  noticed  that  on  land  where  these  fertilizers  are  used 
underground  insect  life  is  scant,  and  direct  experiments  have 
proved  that  this  condition  of  affairs  is  largely  due  to  the  salty 
fertilizers  introduced  into  the  soil.  As  against  peach-lice  in  light 
soil,  ten  pounds  of  kainit  to  a  five-  or  six-year-old  tree  of  good 
size  is  about  right,  and  the  material  should  be  spread  on  the 
surface  evenly  as  far  as  the  roots  are  likely  to  extend. 

In  the  more  normal  plant-lice  the  wings  are  better  developed, 


132 


AN   ECONOMIC  ENTOMOLOGY. 


and  we  find  differences  in  the  form  of  the  honey-tubes  which  are 
of  generic  or  even  sub-family  value.  Thus,  we  have  some  species 
of  Pemphigus  entirely  without  them,  or  with  very  small,  mere 
tubercle-like  structures.  They  live  on  a  variety  of  trees,  but 
perhaps  more  abundantly  on  poplar,  and  make  galls,  which  are 
sometimes  spherical  and  nearly  half  an  inch  in  diameter.  If  we 
cut  one  of  them   after  midsummer,  we  find  it  full  of  plant-lice, 


Fig.  96. 


Cock's-comb  gall  on  elm,  Colopha  ulmicola.—a,  elm-leaf  showing  galls;  b,  winter 
egg,  covered  by  the  skin  of  the  true  female;  c,  larva  just  hatched  ;  d,  pupa;  e,  winged 
adult. 

the  progeny  of  the  single  specimen  which  caused  the  growth  of 
the  gall  early  in  the  season.  There  are  many  other  gall-producing 
lice,  perhaps  the  best-known  being  the  Colopha  ulmicola,  found  on 
elm,  and  forming  the  "cock's-comb"  gall.  The  popular  name 
fairly  describes  the  appearance  of  the  abnormal  growth,  which 
is  an  inch  or  more  in  length  and  about  one-quarter  of  that  in 
height.  None  of  these  gall-making  species  are  abundant  enough 
to  be  seriously  troublesome  ;  but  quite  the  contrary  is  true  of  the 


THE    INSECT   WORLD. 


133 


Woolly  apple-louse,  Schizoneura  lanigera:  show- 
ing a  group  of  specimens  on  bark,  a  crevice  on  a 
branch,  in  which  they  congregate,  and  a  winged 
form. 


"  woolly  plant-lice,"  belonging  to  the  genus  Schizoncura.  These 
cover  themselves  with  a  secretion  resembling  fine  cottony  fibre, 
which  conceals  them  more  or  less  completely.  Thus  there  may 
appear  to  be  tufts  of  cot  .,  , 

ton  attached  to  leaves 
or  twigs,  beneath  each 
of  which  we  find,  how- 
ever, a  great  mass  of 
plant  lice  busily  en 
gaged  in  feeding.  The 
' '  alder  -  blig'ht' '  and 
' '  beech-blight' '  are  due 
to  species  of  this  kind, 
and  more  important 
than  all  is  the  ' '  apple- 
blight,"  or  "  the  woolly 
apple-louse. ' '  This  spe- 
cies, Schizoncura  la7ii- 
gera,  has  been  intro- 
duced into  other  countries,  and  is  known  in  England  and  Aus- 
tralia as  the  "American  blight."  Young  trees  are  frequently 
injured  by  these  aphids,  which  gather  in  masses  on  the  trunks, 
and  cause  the  death  of  the  bark  below  the  point  of  attack.  The 
eggs    may    be    found 

singly     in     the     bark  ^'^-  98- 

crevices  during  win- 
ter, completely  envel- 
oped in  the  dry  skin 
of  the  female,  and 
from  them  appear,  in 
spring,  agamic,  wing- 
less forms,  which  bear 
living  young.  This 
method  of  reproduc- 
tion continues  until  the 
winged  type,  which 
spreads  to  other  localities,  is  produced  in  late  summer.  The 
sexed  forms  are  wingless  and  mouthless,  the  female  producing 
only  a  single  Q^g  ;  but  in  the  southern  parts  of  our  country  it 


Schizoneura  latiigera.  root  form. — a,  galls  caused  by 
them  on  apple-roots  ;  b,  wingless,  wax-coated  form  ;  c. 
winged  form. 


134  ^^   ECONOMIC   ENTOMOLOGY. 

is  not  unusual  for  tlie  insects  to  survive  winter  in  the  adult  con- 
dition, without  producing  a  winter  &^%.  One  form  of  the  species 
works  deep  underground  on  the  fibrous  roots  ;  and  this  is  most 
difficult  to  deal  with,  and  often  causes  the  death  of  the  attacked 
trees.  When  they  appear  on  the  trunk,  treatment  with  either 
whale-oil  soap  or  kerosene  emulsion  will  be  effective,  and  the 
underground  form  can  be  reached  with  bisulphide  of  carbon,  or 
by  a  liberal  use  of  the  tobacco  or  kainit,  as  recommended  on  a 
previous  page. 

We  have  a  number  of  species  that  attack  our  common  orchard 
and  farm  crops,  like  the  cherry-aphis,  Myziis  cerasi,  the  peach- 
louse,  Aphis  persicae-niger,  the  apple-louse.  Aphis  mali,  the 
hop-louse,  wheat-louse,  melon-louse,  and  others  of  equal  reputa- 
tion. Almost  every  species  requires  different  treatment,  and  it 
is  difficult  to  lay  down  general  rules.  Cabbage-lice,  which  fre- 
quently do  great  injury,  can  be  kept  down  by  the  prompt  removal 
of  all  plant  remnants  left  in  the  field  after  the  heads  are  taken  out 
and  disposed  of  On  the  stumps  the  insects  continue  to  breed 
and  live  during  the  winter,  if  not  disturbed,  either  as  eggs  or 
adults  ;  therefore,  remove,  use  up,  or  destroy  them  as  soon  as 
may  be.  In  pits  where  cabbage  is  kept  to  obtain  seed  the  year 
following,  a  great  number  of  lice  pass  the  winter  safely,  but  a  free 
use  of  bisulphide  of  carbon  will  result  in  their  destruction,  so  that 
the  plants  may  be  set  without  infestation  in  spring.  An  equally 
important  point  is  keeping  down  all  cruciferous  weeds  Uke  mus- 
tard, shepherd' s-purse,  and  the  like,  because  on  these  the  insect 
flourishes  as  well  as  on  cabbage  ;  therefore,  clean  culture,  not 
only  in  the  fields  but  along  fences  and  roads,  will  pay  over  and 
over  again.  The  corn-root  louse  can  best  be  attacked  through 
its  guardian  ant,  which  colonizes  the  helpless  forms  upon  the 
roots  in  spring.  Late  fall-plowing  the  corn-fields  is  indicated 
here,  that  the  nests  of  the  ants  may  be  destroyed  at  a  season 
when  they  are  unable  to  rebuild  them.  In  those  sections  where 
fertilizers  must  be  used,  the  kainit  and  nitrate  of  soda,  already 
referred  to,  will  prove  effectual.  The  ' '  apple-louse' '  and  ' '  cherry- 
louse,"  though  different  in  appearance  and  habits,  have  a  similar 
life  history,  and  both  pass  the  winter  in  the  &gg  state,  the  eggs 
being  laid  on  young  twigs  close  to  the  buds.  It  is  good  policy 
to  trim  a  tree  on  which  there  are  many  eggs  pretty  thoroughly  in 


THE    INSECT    WORLD. 


135 


winter,  the  cuttings,  of  course,  to  l)e  i)roni|)tly  destroyed.  Thus 
the  number  of  individuals  to  start  new  infestation  in  spring 
will  be  greatly  reduced.  They  breed  aganiically  throughout  the 
summer,  and  bring  forth  the  sexed  individuals  late  in  fall  or 
early  in  winter.  I  found  them  in  New  Jersey  still  ovipositing 
during  the  first  week  in  Deceml)er.  Where  pruning  is  not  de- 
sirable, much  can  be  done  by  spraying  the  trees,  as  soon  as  the 
eggs  have  hatched,  with  kerosene  emulsion, — say,  one  part  in 
twelve  or  thirteen  of  water.  Both  of  these  species  lay  a  number 
of  eggs,  but  how  many  has  not,  I  believe,  been  actually  deter- 
mined. The  species  that  infests  hops  has  been  already  mentioned, 
and  the  best  remedy  again.st  it  is  the  total  destruction  of  the  vines 
immediately  after  the  hops  have  been  gathered,  which  will  head 
off  the  production  of  the  sexes.  If  this  is  delayed,  spraying  the 
plum-trees  in  fall  or  early  in  the  spring  before  the  hop-vines  have 
made  much  start  will  be  of  great  advantage.  When  the  insects 
infest  such  plants  as  wheat,  rye,  or  oats,  it  becomes  difficult  to 
adopt  measures  likely  to  be  of  much  benefit.  They  multiply  so 
rapidly,  and  the  task  of  spraying  a  wheat-field  is  so  enormous, 
that  it  is  hardly  worth  while  to  recommend  it.  In  such  cases 
we  must  stimulate,  to  assist  the  plants  in  outgrowing  injury,  by 
applying  such  readily  soluble  fertilizers  as  nitrate  of  soda.  This 
gives  additional  vigor  to  the  plant,  enabling  it  to  sustain  the 
attacks  of  the  insect  and  mature  a  crop  as  well.  Harvesting 
should  not  be  delayed  longer  than  absolutely  necessary,  unless  it 
is  observed  that  the  enemies  of  the  plant-lice  are  getting  the  bet- 
ter of  them,  and  in  that  case  nothing  will  be  lost  by  leaving  the 
grain  as  long  as  desirable.  The  aphid  infesting  cucumber-  and 
melon-vines  has  been  recently  determined  to  be  the  same  as  one 
of  those  infesting  oranges,  and  as  that  which  frequently  injures 
cotton.  It  has  also  been  found  on  the  strawberry,  and  seems, 
indeed,  to  be  a  very  general  feeder,  passing  the  winter  upon 
such  wild  plants  as  remain  more  or  less  green.  Under  favorable 
circumstances  it  increases  rapidly  in  spring,  and  a  migration 
starts  to  cultivated  fields.  Against  this  insect  on  melon-vines 
we  can  use  bisulphide  of  carbon,  covering  the  plants  with  a  bowl 
or  other  covering,  and  evaporating  a  small  quantity  beneath  it. 
This  will  kill  the  aphids  in  about  an  hour,  and,  though  the  pro- 
cess is  slow,  it  has  the  advantage  of  being  completely  effective. 


136  AN   ECONOMIC   ENTOMOLOGY. 

While,  as  has  been  stated,  we  cannot  lay  down  general  rules 
as  to  the  treatment  of  all  plant-lice,  there  are  a  few  points  that 
are  always  important.  In  the  first  place,  the  earlier  the  insects 
are  dealt  with,  the  more  chance  there  is  for  the  application  to  be 
effective.  Plant-lice  should  be  treated  just  as  soon  as  they  are 
noticed  ;  the  longer  the  delay  the  weaker  the  plants  become,  and 
the  greater  the  thoroughness  required  to  reach  all  the  specimens. 

As  a  general  insecticide,  nothing  is  better  than  the  kerosene 
emulsion,  which,  when  diluted  ten  times  with  water,  kills  all  the 
young  forms  and  adults  of  the  green  species.  It  has  been  found 
by  experiment  that  black  or  brown  species  are  much  more  diffi- 
cult to  destroy,  and  one  part  of  emulsion  in  six  or  eight  parts  of 
water  is  more  likely  to  be  effective.  Fish-oil  soap  is  effective  at 
the  rate  of  one  pound  in  six  gallons  of  water  ;  or,  as  against  the 
brown  species,  one  pound  in  four  gallons  of  water.  Thorough- 
ness of  application  is  always  essential.  It  must  be  remembered 
that  these  poisons  act  by  clogging  the  spiracles,  or  by  entering 
into  the  body  through  them.  Unless  the  application  is  thorough, 
the  insects  may  be  weakened  but  not  killed,  or,  if  rendered  help- 
less for  a  time,  they  may  recover,  and  a  second  dosing  becomes 
necessary  where  one,  more  thoroughly  applied,  would  have  been 
sufficient.  Where  it  is  not  advisable  to  apply  either  of  the  ma- 
terials mentioned,  we  can  use  tobacco  with  good  prospects  of 
success,  either  as  a  decoction  or  a  very  finely  ground  powder. 
In  greenhouses,  tobacco  is  a  standard  remedy,  and  its  frequent 
application  results  in  keeping  them  moderately  free  from  these 
pests.  It  may  be  applied  as  already  described,  but  is  more  usu- 
ally burnt  to  make  a  smoke,  which  is  poisonous  to  the  insects. 
A  milder  method  is  to  keep  the  steam-pipes  covered  with  moist 
stems,  so  as  to  produce  a  nicotine-laden  atmosphere.  Very  often 
plant-lice  appear  in  forcing-beds,  and  these  we  can  generally 
destroy  with  bisulphide  of  carbon  placed  in  a  shallow  dish  and 
left  in  the  covered  beds  overnight.  Greenhouse  benches  may 
be  rid  of  the  pests  in  the  same  way,  covering  the  plants  for  two 
or  three  hours  with  a  frame  or  box,  and  evaporating  a  small 
quantity  of  the  bisulphide.  A  fumigating-box  made  of  wood, 
canvas,  tin,  or  other  material,  large  enough  to  contain  potted 
plants  of  good  size,  should  be  in  every  greenhouse  and  nursery. 
A  number  of  pots  of  infested  plants  may  be  placed  in  such  a  box. 


THE    I  A- SECT    WORLD. 


137 


the  door  closed,  and  bisulphide  evaporated  Iroiii  a  vessel  hung  up 
just  below  the  top  of  the  box.  As  the  vapors  descend,  they  will 
kill  the  inserts  infesting  the  plants,  which  may  then  be  sent  out 
free  from  all  insect  troubles.  One  dram  of  liquid  per  cubic  foot 
of  space  will  be  about  the  right  quantity  not  likely  to  hurt  vege- 
tation, while  killing  all  lice  by  the  time  the  liquid  has  entirely 
evaporated. 

The  "jumping  plant-lice"  are  so  called  from  their  habit  of 
leaping  readily,  though,  as  a  matter  of  fact,  their  resemblance  is 
rather  to  the  tree-hoppers,  and  most  of  all  they  recall  a  miniature 


Fig.  99. 


The  pear-psylla. — a,  pupa  from  under  side,  showing  the  thread-like  piercing  lancets; 
to  the  right,  a  winged  adult  and  stalked  egg. 

cicada.  They  all  belong  to  the  family  Psyllidce,  some  species  of 
which  are  exceedingly  troublesome, — e.g.,  the  "pear-psylla," 
Psylla  pyricola.  This  infests  pear-trees  in  the  more  northern 
parts  of  the  country,  extending  south  to  Maryland,  though 
south  of  New  York  State  it  occurs  in  isolated  patches  only.  It 
does  its  injury,  first,  by  sucking  the  juices  of  the  plant  and  so 
weakening  it ;  second,  it  exudes  honey-dew  in  such  quantity  as 
actually  to  close  the  pores  of  the  leaves  and  young  bark,  over 
which  a  fungus  forms  and  checks  growth.  It  commonly  attacks 
the  stalk  of  the  fruit,  or  the  twig  just  where  it  is  fastened,  and 
the  result  is  nearly  always  a  cessation  of  growth  in  the  pear  itself. 
The  species  has  several  broods  during  the  season,  bift  winters  as 


138  AN  ECONOMIC   ENTOMOLOGY. 

an  adult  in  any  available  shelter, — under  loose  bark  of  trees,  under 
rubbish,  and,  in  fact,  wherever  there  is  an  opportunity  to  hide. 
The  application  of  whale-oil  soap  early  in  spring,  just  as  the  buds 
begin  to  swell,  will  generally  kill  the  insects,  which  are  then  ready 
to  emerge  from  winter  quarters.  Good  practice  is  to  scrape  all 
the  loose  bark  from  the  trees  during  the  winter,  and  burn  it  ; 
wash  at  that  time  with  a  potash  or  strong  kerosene  mixture,  and 
in  spring  use  the  whale-oil  soap  at  the  rate  of  one  pound  in  one 
gallon  of  water,  being  careful  to  confine  the  spraying  to  the 
trunk  and  larger  branches.  If  this  is  thoroughly  done,  it  forms 
a  film  over  the  trunk  which  no  insect  will  voluntarily  pierce,  A 
liberal  application  of  whitewash  is  also  advantageous,  and  should 
be  put  on  with  a  knapsack  sprayer  and  Vermorel  nozzle. 

We  have  many  species  belonging  to  this  family,  some  of  them 
gall-makers  on  the  hackberry,  or  Celtis  ;  but  none  others  occur  in 
sufficient  numbers  to  be  of  economic  importance. 

The  ' '  tree-hoppers' '  belong  to  the  family  Membracidce,  and 
contain  many  odd-looking  types.  The  general  shape  has  been 
compared  to  a  beech-nut,  and  the  most  prominent  part  is  always 
the  thorax,  which  may  be  produced  into  a  curved  horn  forward, 
into  a  broad  hump,  into  a  pair  of  curved  lateral  horns,  into  a 
double  hump,  or  into  a  dozen  other  forms.  The  species  occur 
on  trees,  shrubs,  vines,  and  indeed  on  vegetation  generally, 
though  rarely  in  great  numbers.  Some  species  excrete  honey- 
dew,  some  lay  their  eggs  in  white  frothy  masses  on  plants,  and  a 
few  are  attended  by  ants,  thus  resembling  the  plant-lice.  Only 
a  few  are  troublesome,  and  of  these  are  the  "buffalo  tree- 
hoppers,"  belonging  to  the  genus  Ceresa.  They  derive  their 
common  name  from  the  fact  that  the  thorax  is  cut  ofT  square 
anteriorly,  and  projects  into  two  short,  lateral,  curved  horns, 
which  give  it  a  fanciful  resemblance  to  the  massive  front  of  a 
buffalo.  The  head  is  small  and  scarcely  noticeable,  the  horns 
not  being  recognized  at  first  as  really  belonging  to  the  thorax. 
This  insect  causes  injury  by  laying  its  eggs  in  slits  on  twigs  of 
apple-  and  other  fruit  trees.  There  appears  to  be  almost  a  poi- 
soning of  the  plant  tissue,  because  the  wounds,  though  apparently 
slight,  do  not  readily  heal  over,  but  rather  open  up  the  year 
following,  giving  rise  to  an  abnormal  swelling,  weak  and  morbid 
in  character,  unable  to  sustain  the  weight  of  any  fruit  that  occurs 


7HE    INSECT    WORLD. 


139 


beyond  it,  and  ready  to  break  in  the  (irj,t  iiigh  wind.  On  old  or 
large  trees  the  insects  are  rarely  dangerous,  because  their  injury 
results  in  only  a  litde  pruning,  but  on  young  trees  they  may 
cause  deformities  ;  hence,  if  the  insects  are  noticed  in  a  young 
orchard,  it  will  be  advisable  to  go  over  it  carefully  during  the 
winter,  to  trim  out  all  infested  twigs  or  branches,   burning  the 

Fig.  100. 


Buffalo  tree-hopper,  Ceresa  btibalus.—a,  adult;  b,  c,  d,  tarsus,  antenna,  and  wing;  /,  ^, 
tip  of  abdomen,  showing  ovipositor. 


cuttings  to  destroy  the  eggs.     Active  insecticide  applications  are 
hardly  indicated. 

Next  come  the  cicadas,  or  "harvest-flies,"  often  miscalled 
locusts,  and  the  largest  of  the  Homoptera.  They  are  easily  known 
by  their  broad,  transparent  wings,  the  large  head  with  prominent 
eyes  set  on  each  side,  and  by  their  intensely  shrill,  loud  song, 
which  during  midsummer  forms  one  of  the  common  sounds 
of  the  country.  The  author  of  this  concert  is  the  ' '  dog-day 
har\'est-fly,"  greenish  in  color,  more  or  less  marked  with  black. 
The  noise  is  produced  by  an  elaborate  drumming  and  resonating 
structure  on  the  under  side  of  the  thorax  and  abdomen  of  the 


140 


AN   ECONOMIC   ENTOMOLOGY. 


males,  who  alone  are  musical,  giving  rise  to  that  oft-quoted  old 
saying,— 

'  "  Happy  the  cicadas'  lives, 

For  all  have  voiceless  wives." 

The  plan  of  the  sound-organs  can  best  be  described  by  com- 
paring to  a  slightly  convex-bottomed   tin  pan,  which  makes  a 


Fig.  lor. 


I 


Fig.  I02. 


a,  Ceresa  bubalus.  ovipositing  in  slits  b  ;  the 
eggs,  d,  arranged  as  at  c ;  old,  scarred  punc- 
tures shown  at  e. 


The  dog-day  harvest-fly, 
Cicada  tibicen. 


snapping  noise  whenever  the  bottom  is  forced  to  change  from 
convex  inwardly  to  convex  outwardly.  By  an  exceedingly  rapid 
snapping  of  the  convex  "drum"  of  the  cicada,  the  continuous 
shrilling  sound  is  produced,  intensified  and  modified  by  the  vari- 
ous tense  membranes  more  or  less  surrounding  it. 

The  most  famous  species  of  this  family  is  the  "periodical 
cicada,"  or  "seventeen-year  locust,"  Cicada  septendecim.  It  is 
of  especial  interest  from  the  unusually  long  larval  period,  re- 
maining in  the  Middle  and  Northern  States  sixteen  years  beneath 


THE    INSECT   WORLD. 


141 


the  surface  of  the  ground,  feeding  on  the  juices  of  roots,  and 
transforming  in  the  spring  of  the  seventeenth  year  into  a  winged 
adult.  No  less  than  twenty-two  broods  have  been  tabulated  in 
the  United  States,  chiefly  through  the  efforts  of  the  late  Dr.  C. 
V.  Riley,  so  that  we  know  approximately  how  each  is  distributed, 
and  are  able  to  foretell  with  certainty  when  the  insects  will  appear 
and  about  what  territory  they  will  cover.     A  further  point  of 

F^iG.  103. 


The  periodical  cicada,  C  septendecim. — a,  pupa,  ready  to  change;  b,  pupa-skin  from 
which  the  adult  c  has  emerged  ;  e,  eggs,  taken  from  the  egg-punctures  d. 


interest  is  that  in  the  more  southern  States  the  period  of  develop- 
ment is  somewhat  shorter,  thirteen  years  only  being  required  to 
bring  the  insect  to  maturity.  Much  confusion  was  caused  in 
arranging  the  broods  until  this  fact  was  understood  ;  but  experi- 
ments have  now  been  made  in  transferring  eggs  of  the  thirteen- 
year  variety  to  northern  regions,  and  eggs  of  the  seventeen-year 
variety  to  southern  regions  ;  the  object  being  to  ascertain  whether 
climate  would  affect  the  larval  period  in  the  first  generation. 
These  experiments  have  not  yet  terminated.  This  cicada  makes 
up  for  the  long  intervals  at  which  it  occurs  by  the  enormous 
numbers  in  which  it  appears,  and  in  a  "  locust' '   year  its  loud 


142 


AN  ECONOMIC   ENTOMOLOGY. 


Fig.  104. 


song  may  be  heard  at  all  periods  of  the  day  and  until  late  into 
the  night,  from  the  end  of  May  to  nearly  the  end  of  June,  louder 
and  more  intense  on  warm  or  hot  days.  No  injury  is  done  by 
the  insects  in  feeding,  but  their  egg-laying  habits  often  cause 

considerable  trouble.  Though 
the  larvae  feed  under  ground,  the 
eggs  are  laid  in  the  twigs  and 
branches  of  trees  ;  a  series  of  slits 
being  cut  by  the  powerful  ovi- 
positor of  the  female,  forming 
smooth  chambers  in  which  the 
eggs  are  arranged  in  series. 
There  is  nothing  to  be  done  when 
such  a  brood  occurs  except  take 
the  injury  and  make  the  best  of 
it.  Of  course  valuable  plants  or 
trees  can  be  protected  by  mos- 
quito-netting, but  my  statement 
applies  to  ordinary  farm  and  or- 
chard crops.  The  fact  that  we 
know  when  the  insects  are  to 
appear  makes  it  possible  for  the 
fruit-grower  to  guard  himself  to 
some  extent  by  not  setting  out 
young  stock.  On  old  trees  no 
serious  injury  will  be  done,  and 
if  no  pruning  is  attempted  during 
the  winter  preceding,  the  insects 
will  probably  find  an  abundance 
of  useless  twigs  to  oviposit  in. 
Young  trees,  however,  are  some- 
times so  injured  as  to  make  them 
practically  useless,  either  by  com- 
pletely spoiling  the  shape,  or  by 
so  weakening  the  main  branches 
that  they  never  become  strong  enough  to  bear  a  proper  top. 
Wherever  the  English  sparrow  has  been  introduced,  the  period- 
ical cicada  is  doomed.  These  birds  seem  to  have  an  intense 
hatred  for  the  insects,  attacking  and  pulling  them  to  pieces  in 


Cicada    egg-punctures :     at    a,    freshly 
made;  at  b,  old  and  distended. 


THE    IXSECT   WORLD. 


M3 


the  most  wanton  manner.  Near  the  large  cities  where  the  spar- 
rows are  numerous,  entire  broods  have  already  been  destroyed. 
In  1889  the  insects  appeared  in  large  numbers  in  Prospect  Park, 
Brooklyn,  and  in  the  surrounding  woodland,  but  in  an  entire 
day's  careful  search  I  found  only  a_  single  branch  containing 
eggs  ! 

That  it  may  be  known  in  a  general  way  where  and  when  these 
insects  may  be  expected,  the  following  record  of  the  broods  is 

Fig.   105. 


1]  ;'| 

; 

'1  I/I 

i 

1 

i 

' 

Cicada  egg-punctures,  seen  at  a,  from  outside  ;  5,  cut  down  on  puncture  to  show  the 
two  chambers  ;  c,  side  view  of  an  egg-chamber  ;  d,  a  pair  of  egg-chambers  from  which 
the  eggs  have  been  removed. 


given,  with  the  date  of  last  appearance,  the  time  when  they  may 
be  next  expected,  and  the  country  covered  by  them.  The  state- 
ment is  made  up  from  the  reports  and  bulletins  of  the  United 
States  Department  of  Agriculture. 

Brood  I.  last  appeared  in  1893  !  ^^'^^1  appear  again  in  1910. 
Occurs  in  Massachusetts  and  Connecticut  in  small  numbers. 

Brood  II.  appeared  last  in  1895  ;  will  appear  again  in  1908. 
It  covers  the  northwestern  part  of  Georgia,  and  appears  at  thir- 
teen-year intervals.  No  very  definite  limits  have  been  assigned 
to  it. 

Brood  III.,  originally  supposed  to  occur  in  Ohio  in  1887,  was 
based  on  erroneous  information. 

Brood  IV.  is  of  the  thirteen-year  variety,  appeared  last  in 
1883,  and  will  appear  again  in   1896,  covering  parts  of  Florida. 


144 


AN  ECONOMIC   ENTOMOLOGY. 


Alabama,  Mississippi,  and  Tennessee,  but  it  seems  not  to  be 
very  numerous. 

Brood  V.  occurred  last  in  1888  and  will  appear  next  in  1905. 
It  covers  parts  of  Southern  Wisconsin,  Northern  Illinois,  the 
eastern  third  of  Iowa,  the  northwest  counties  of  Indiana,  and  the 
more  southern  part  of  Michigan.  This  brood  is  very  numerous 
in  individuals. 

Brood  VI.  occurred  last  in  1884  and  will  occur  again  in  1897, 
being  of  the  thirteen-year  race.  It  occurs  in  the  southwestern 
part  of  Mississippi  and  extends  into  Louisiana,  infesting  a  com- 
paratively small  territory  only. 

Brood  VII.  occurred  last  in  1885,  and  will  occur  again  in 
i8g8,  being  also  of  the  thirteen-year  race.  It  occurs  in  South- 
ern Illinois,  Kansas,  Missouri,  Georgia,  Louisiana,  Arkansas, 
Mississippi,  and  Tennessee. 

Brood  VIII.  appeared  last  in  1889,  and  will  appear  again  in 
1906.  It  covers  a  portion  of  Southern  Massachusetts,  a  large 
part  of  Long  Island,  extends  along  the  Atlantic  Coast  to  the 
Chesapeake  Bay  and  for  some  distance  into  Pennsylvania,  Ken- 
tucky, West  Virginia,  Ohio,  Indiana,  and  Illinois 

Brood  IX.  occurred  last  in  1891  and  will  appear  again  in  1908. 
It  occurs  in  parts  of  Nebraska  and  probably  in  portions  of  Colo- 
rado, though  it  has  not  yet  been  satisfactorily  limited. 

Brood  X.  occurred  last  in  1888  and  will  appear  again  in  1901, 
being  of  the  thirteen-year  race.  It  has  been  recorded  from  Texas, 
but  is  yet  a  doubtful  brood,  requiring  fuller  observations  than 
have  been  made  to  substantiate  it  positively. 

Brood  XI.  occurred  in  1893  and  will  occur  again  in  1910.  It 
is  a  large  one,  covering  parts  of  North  Carolina,  Virginia,  Mary- 
land, Illinois,  and  Indiana,  although  not  the  entire  State  in  any 
instance. 

Brood  XII.  occurred  last  in  1894  '^"d  will  make  its  next  ap- 
pearance in  191 1.  It  extends  along  both  sides  of  the  Hudson 
for  its  full  length,  into  Southern  New  York,  Connecticut,  through 
the  entire  State  of  New  Jersey,  and  into  Pennsylvania,  Ohio, 
Michigan,  North  Carolina,  Virginia,  Maryland,  and  Delaware. 

Brood  XIII.  appeared  in  1895  and  will  appear  again  in  1912. 
It  occurs  throughout  a  large  part  of  Iowa,  and  probably  a  portion 
of  Illinois  and  Missouri. 


THE    INSECT   WORLD. 


145 


Brood  XIV.  will  appear  in  1896,  and  covers  Western  Missouri, 
extending  into  Kansas,  Arkansas,  Iowa,  Northern  Texas,  and 
Indian  Territory. 

Brood  XV.  will  occur  in  1897  in  Western  Pennsylvania  and 
Ohio,  extending  into  Kentucky  and  West  Virginia. 

Brood  XVI.  appeared  last  in  1893  and  will  appear  again  in 
1906,  being  of  the  thirteen-year  race.  It  occurs  in  the  northern 
portion  of  Georgia,  but  its  limits  are  not  well  defined. 

Brood  XVII.  will  appear  next  in  1898  and  at  intervals  of 
seventeen  years  thereafter.  It  occurs  in  Wisconsin,  the  north- 
ern part  of  Ohio,  Pennsylvania,  and  parts  of  New  York,  as  well 
as  isolated  localities  in  New  Jersey.  The  brood  is  a  small  one, 
however,  especially  in  the  southern  part  of  its  range,  and  appar- 
ently dying  out. 

Brood  XVIII.  occurred  in  1894  and  will  occur  again  in  1907, 
being  of  the  thirteen-year  race.  It  is  a  very  well-recorded  one, 
and  covers  Southern  Illinois,  nearly  all  of  Missouri,  Louisiana, 
Arkansas,  Indian  Territory,  Kentucky,  Tennessee,  Mississippi, 
Alabama,  Georgia,  North  and  South  Carolina. 

Brood  XIX.  occurred  last  in    1882  and  will  occur  again  in 

1899.  It  is  a  small  one  and  confined  to  a  few  counties  in  Central 
and  Northern  New  York,— that  is,  Monroe,  Livingston,  Madi- 
son, Yates,  and,  perhaps,  those  immediately  adjoining. 

Brood   XX.  appeared  last  in   1883  and  will  appear  again  in 

1900.  It  occurs  in  Western  New  York  and  Pennsylvania  and 
Eastern  Ohio.     It  is  a  small  brood  and  does  not  attract  attention. 

Brood  XXI.  occurred  last  in  1884  and  will  occur  again  in 

1901.  It  covers  parts  of  North  Carolina,  Virginia,  and  West 
Virginia,  and  may  possibly  occur  in  Massachusetts  (Martha's 
Vineyard)  as  well. 

Brood  XXII.  appeared  last  in  1885  and  will  appear  again  in 

1902.  It  occurs  on  Long  Island,  in  New  York,  New  Jersey, 
Pennsylvania,  Delaware,  Maryland,  District  of  Columbia,  Vir- 
ginia, West  Virginia,  North  Carolina,  Tennessee,  Georgia,  Ohio, 
Kentucky,  Indiana,  Illinois,  Michigan,  and  Wisconsin.  Brood 
VI L,  of  the  thirteen-year  race,  and  Brood  XXII. ,  of  the  seventeen- 
year  race,  come  in  contact  in  Southern  Illinois  and  Northern 
Georgia,  and  it  may  happen,  as  it  did  in  1885,  that  these  two 
broods  appear  during  the  same  year  at  the  same  place. 

10 


146 


AN  ECONOMIC  ENTOMOLOGY. 


The  FjilgoridcB^  or  ' '  lantern-flies, ' '  contain  some  very  remark- 
able and  striking  species  in  tropical  countries,  but  are  sparsely- 
represented    by   somewhat   rare 
Fig.  106.  species  in  our   fauna.     Perhaps 

the  most  comraon  of  our  forms 
are  species  m^On}ie?iis,  pale 
green  or  whitish,  having  some- 
what  the    appearance    of   small 


wedges,  the  broad  wing-covers 
being  flattened  vertically.  They 
may  be  found  on  the  under  side 
of  leaves  of  various  plants,  par- 
ticularly grape,  sucking  the 
juices,  preferably  from' the  larger 
veins  or  ribs.     None  of  them  are 

injurious,  and  the  family  is  mentioned  only  that  our  common 

species  may  be  recognized. 

The  "spittle-insects,"  or  "frog-hoppers,"  of  the  family  Cer- 

copida,  resemble  some  forms  of  tree-hoppers  in  their  habit  of 

laying    the    eggs    in    little, 


FulgoriAcB ,  or  lantern-flies. — a,  Scolops 
sulcipesY^b,  Poeciloptera  truncaticorms  ; 
twice  natural  size. 


^  Fig. 


107. 


frothy,  white  masses.  These 
masses  of  ' '  frog-spittle' '  are 
often  noticed  in  grass  lands, 
but  their  true  character  is 
rarely  understood.  Unlike 
the  "tree-hoppers,"  the 
Cercopidce  never  have  horn- 
like processes  or  projections, 
but  are  usually  squat,  some- 
what angular,  yet  flattened 
creatures,  whose  popular 
name,  "frog-hoppers,"  has 
been  obtained  by  the  some- 
what fanciful  resemblance  of  the  insects  to  a  frog  when  just  ready 
to  leap.  Few  of  these  species,  so  far  as  I  have  any  information, 
are  sufliciently  injurious  to  be  of  economic  importance.  They 
feed  on  a  great  variety  of  plants,  but  are  rarely  common  on  culti- 
vated crops. 

It  is  different  with  the  "leaf-hoppers,"  or  Jas sides,  which  are 


Cercopid,  or  spittle-insect. — a,  larva,  en- 
larged; d.same,  natural  size,  on  a  leaf  bearing 
"frog-spittle;"  c,  the  adult,  enlarged. 


THE    INSECT   WORLD. 


147 


small,  slender  insects  with  the  wing-covers  narrow  and  slightly 
thicker  than  the  broad  hind  wings,  which  are  the  only  effective 
organs  of  flight.  The  thorax  is  broad  and  square,  the  head 
usually  short  and  very  broad,  in  most  cases  somewhat  crescent- 
shaped,  with  prominent  eyes  occupying  a  large  part  of  the  sides. 
If  we  examine  the  insects  on  the  under  side  it  appears  as  if  the 
beak  or  rostrum  came  out  from  the  breast  between  the  front  legs, 
so  much  is  the  head  curved  under.  The  antennae  are  very  short 
and  bristle-like  ;  the  legs  are  well  developed,  the  hind  pair  espe- 
cially being  very  long  and  powerful,  set  with  spines  on  the  tibiae, 

Fig.  108. 


Development  of  a  Jassid,  Agallia  sanguinolenta.—a,  larva;  b,  pupa;  c,  adult;  also  head 
of  same  from  below. 


somewhat  as  in  the  grasshoppers,  and  like  them  the  insects  are 
powerful  leapers.  This  they  are  in  all  stages,  but  as  adults  they 
are  also  ready  fliers,  and  hence  difficult  to  capture.  Many  of 
them  are  common  and,  feeding  on  cultivated  plants,  are  injurious. 
As  in  other  families,  there  is  considerable  difference  in  the  life 
history  of  the  species  ;  but  of  most  of  those  of  economic  impor- 
tance it  may  be  said  that  they  pass  the  winter  in  the  adult  stage, 
hiding  in  all  sorts  of  rubbish  or  in  crevices,  wherever  they  find 
opportunity.  Some  time  in  spring  they  leave  their  winter  quar- 
ters, attack  the  plants  upon  which  they  feed,  and  lay  eggs.  The 
number  of  hibernating  individuals  is  usually  not  very  great,  but 
they  lay  a  large  number  of  eggs,  and  the  young  and  future  broods 
become  troublesome.      One  of  the  best-known  species  is  that 


148 


AN   ECONOMIC   ENTOMOLOGY. 


The  grape-leaf-hopper,  Erythroneura  vitis ;  at  rest, 
and  with  wings  expanded. 


found  on  grape-vines,  which  causes  the  leaves  during  the  latter 
part  of  the  summer  to  become  marked  with  brown  spots,  some- 
tmies  in  such  numbers  that  they  become  confluent  and  the  entire 
leaf  is  "burnt."  If  we  tap  a  leaf  at  this  time  swarms  of  little 
creatures,  not  exceeding  an  eighth  of  an  inch  in  length,  prettily 

marked  with  green,  rosy- 
^'^-  '°9-  red,  and  yellow,  will  fly 

or  jump  from  them. 
Earlier  in  the  season 
they  are  yellow  or  green- 
ish, without  wings,  but 
jump  readily  if  disturbed. 
On  roses  we  find  a  simi- 
lar appearance,  and  here 
the  species  are  green  or 
yellowish,  without  much 
marking.  Many  are  the  crops  infested  by  these  little  hoppers, 
and,  though  there  are  good  characters  by  which  they  can  be 
distinguished  scientifically,  yet  to  ordinary  observation  they 
appear  much'alike,  except  in  size  and  color. 

The  methods  of  preventing  injury  are  much  the  same  for  all 
species.  In  the  first  place,  where  experience  has  shown  that  the 
insects  are  likely  to  occur  during  the  summer,  all  rubbish  should 
be  disposed  of  in  the  course  of  the  winter  preceding.  This  can 
be  done  by  collecting  and  burning,  or  by  plowing  under  very 
early  and  cultivating  so  as  to  leave  a  clean  field.  Loose  bark, 
dead  branches,  twigs,  or  scaly  fence-posts  should  all  be  attended 
to,  and  piles  of  dead  grass  or  weeds  along  fences  or  in  corners 
should  be  burnt  or  otherwise  destroyed.  In  this  way  much  can 
be  done  to  prevent  the  insects  from  getting  a  start.  When  the 
larvae  are  first  noticed  great  success  has  been  attained  in  vine- 
yards by  walking  along  the  sides  of  vines  strung  oh  wires,  dis- 
turbing them  to  start  the  insects,  which  jump  wildly  and  readily. 
A  shingle  or  palm-leaf  fan  smeared  on  both  sides  with  coal-tar  or 
insect-lime  should  be  kept  in  constant  motion  near  the  vines,  and 
by  this  fanning  a  great  quantity  of  the  jumping  larvae  will  be  drawn 
to  the  smeared  surfaces  and  destroyed.  This  method  is  practical, 
and  has  been  found  effective  within  my  own  experience  ;  so  large 
a  proportion  of  the  insects  being  captured  in  the  course  of  two 


Tlifi    INSECT   WORLD.  1 49 

days  that  subsequently  they  were  not  noticeable.  If  this  method 
cannot  for  any  reason  be  used,  the  kerosene  emulsion  diluted  ten 
times  may  be  applied,  and  the  vines  should  be  disturbed  as  the 
spraying  is  done.  If  a  Vermorel  nozzle  is  used,  it  can  be  held 
a  little  distance  from  the  vines  and  will  hit  the  insects  while  they 
are  in  the  air,  either  jumping  or  flying.  The  wetting  done  in 
this  way  is  as  effective  as  when  done  on  the  leaves,  and  there  is 
even  more  chance  of  hitting  them  in  the  air  than  at  rest.  So  the 
effort  should  be  to  fill  the  air  around  the  vines,  for  some  little 
distance,  with  the  fine  mist-like  spray  so  easily  produced  by  the 
Vermorel  nozzle.  This  method  should  also  be  made  use  of  if  the 
insects  are  found  in  numbers  after  they  are  winged.  It  is  appli- 
cable in  many  cases,  but  hardly  practical  where  insects  feeding 
upon  wheat  or  similar  plants  are  to  be  dealt  with.  It  has  been 
found  that  the  adults  are  attracted  to  light,  and  the  electric  arc- 
light,  particularly,  destroys  myriads  of  them.  I  have  seen  in  a 
single  globe  no  less  than  one  pint  of  leaf-hoppers,  and  the  num- 
ber included  in  that  measure  is  almost  impossible  of  estimate. 
The  unfortunate  feature  in  this  method  is  that  the  damage  to 
vegetation  has  been  done  when  it  takes  effect,  and  it  is  in  the 
line  of  preventing  injury  during  the  year  ensuing,  which  can 
be  accomplished  as  readily  by  the  winter  treatment.  In  fact, 
cleaning  up  during  winter  is  strongly  insisted  upon,  and  will  pay 
many  times  over.  A  great  number  of  leaf-hoppers  are  found  in 
grass  lands,  where  they  do  much  more  injury  than  is  generally 
supposed, — an  experiment  in  Iowa  seeming  to  prove  that  just 
about  one-half  the  crop  is  destroyed  in  badly  infested  fields.  The 
experiment  was  made  by  setting  off  two  patches  of  equal  size,  as 
nearly  equal  in  all  respects  as  could  be  made,  leaving  the  one 
untreated  and  collecting  the  leaf-hoppers  from  the  other.  Cattle 
were  pastured  on  both  parcels,  and  that  on  which  the  insects 
were  collected  supported  just  double  the  number.  The  insects 
were  collected  by  means  of  shallow  pans  coated  with  tar,  drawn 
by  man  or  horse-power,  and  in  jumping  or  flying  up  before  it  they 
alighted  immediately  behind  the  edge,  upon  the  tar.  It  requires 
very  few  such  collections  to  practically  exterminate  the  pests  on 
a  tract  of  land,  but  of  course  the  question  remains  whether  it 
will  pay.  On  grass  lands  winter  treatment  is  hardly  practicable, 
and  collecting  in  pans  is  perhaps  the  only  available  method. 


ISO 


AN  ECONOMIC  ENTOMOLOGY. 


Fig.  iio. 


A  water-boatman,  Notonecta  species. 


Fig.    III. 


The  sub-order  Hetcroptera  conrains  those  species  of  bugs  in 
which  the  upper  wings  are  thickened  toward  the  base  and  the 

terminal  portion  is  membraneous 
and  veined.  We  have  a  large 
number  of  species  belonging  here, 
and  some  large  series  may  be  en- 
tirely left  out  of  consideration. 
Such,  for  instance,  are  the 
aquatic  families,  all  of  which  seem 
to  be  carnivorous  in  habit, 
whether  they  live  on  the  surface 
of  the  water  or  beneath  it.  One 
of  the  water-boatmen,  a  species  of  Corisa,  may  be  mentioned, 
because  its  eggs  are  used  as  food  in  Mexico.  These  eggs  are 
nearly  white  in  color,  about  one-tenth  of  an  inch  in  diameter,  and 
laid  in  great  numbers  on  sedges,  where  they  are  collected  by  the 

natives.  Judging  from  the  usual  odor 
of  the  bugs  and  from  the  taste  of 
such  eggs  as  are  sometimes  involun- 
tarily eaten  on  fruits,  it  requires  a 
specially-developed  gustatory  appa- 
ratus to  enjoy  a  meal  of  this  char- 
acter. This  suggests  the  fact  that 
one  of  the  peculiarities  of  this  sub- 
order is  the  more  or  less  marked 
presence  of  odors,  differing  some- 
what in  kind,  but  all  of  them  intensely 
disagreeable.  In  bed-bugs  we  have 
one  type  in  marked  perfection,  while 
in  the  "squash-bug"  we  find  an  ex- 
cellent illustration  of  another. 

One  of  the  water-bugs  that  some- 
times attracts  attention  is  a  huge 
creature,  two  or  three  inches  in 
length,  broad  in  proportion,  livid 
gray  in  color,  flattened  above,  with 
a  short  beak  and  very  large,  thick- 
ened forelegs,  often  drawn  in  considerable  numbers  to  electric 
lights.     It  is  the  Bdosto7na  americana,  which  lives  in  ponds  and 


Belostonia  americana. 


THE    INSECT   WORLD. 


151 


streams,  where  it  fceds  on  other  insects  and  small  fish,  destroy- 
ing large  numbers.  During  the  night  the  winged  individuals 
leave  the  ponds,  pair,  and  fly  to  new  localities  to  lay  their  eggs. 
So  abundantly  do  they  occur  that  they  sometimes  become  nui- 
sances near  electric  lights,  and  have  been  termed  from  this  fact 
' '  electric-light  bugs. ' ' 

Sometimes  we  find  slender,  spider-like  creatures  of  a  brown 
color  scudding  over  the  surface  of  the  water  at  a  rapid  rate,  and 


Fig.  112. 


A  water-strider,  Rheitmatobates  rileyi,  female. — a,  anterior  tarsus  ;  b,  ovipositor ;  c,  hind 

tarsus. 

these  are  "water  striders,"  or  Hyd^'obatidcs.  They  are  inter- 
esting because  some  of  them  pass  their  entire  lives  upon  the 
ocean,  miles  from  land.  These  are  said  to  feed  upon  the  juices 
of  such  dead  fish  and  other  animals  as  they  find  on  the  surface, 
and  probably  also  on  the  floating  masses  of  sea-weed  occurring 
in  equatorial  regions  where  they  are  most  common. 

The  first  family  of  economic  importance  among  the  terrestrial 
species  is  the  Redtiviidtz,  containing  species  of  quite  large  size. 


152  AAr  ECONOMIC  ENTOMOLOGY. 

distinguished  by  a  comparatively  small,  narrow  head  with  promi- 
nent eyes,  and  by  a  short,  very  stout,  curved,  pointed  beak, 
which  rests,  when  not  in  use,  in  a  little  groove  between  the 
front  legs.  The  insects  are  strongly  built,  with  legs  usually  well 
developed,  and,  as  they  are  predaceous,  are  to  be  regarded  as 

friends.      The   very   small 
F^*^-  ^^3-  head    and    short,    slightly 

yc-j^^21Si^^f—p — -^^  curved,  pointed  beak,  serve 

to  distinguish  them  from 
the  plant-feeding  species. 
They  readily  puncture  the 
skin  of  any  one  handling 
them    carelessly,    and    the 

Wing  of    Heteropteron   with  all    the    regions       <,i  •.    t.  •  ^•       1 

named.  L)ite    IS  cxceedmgly  pam- 

ful,  the  poison  injected 
into  the  wound  being  intensely  irritating,  and  sometimes  causing 
considerable  swelling,  with  pain  lasting  for  days.  One  of  the 
species  has  adapted  itself  to  life  in  houses,  feeding  upon  flies  and 
bed-bugs.  The  young  have  the  curious  habit  of  coating  them- 
selves with  particles  of  dust  or  fibre  which  conceals  them  perfectly 
from  casual  observation.  A  similar  species,  Conorhinus  sangui- 
sugis,  nearly  an  inch  in  length,  is  found  in  houses  in  the  South- 
ern States, — not  to  feed  on  bed-bugs,  however,  but  as  a  bed-bug 
itself  It  is  especially  inclined  to  bite  children,  and  many  cases 
of  supposed  spider-bites  are  believed  by  Dr.  Leconte  to  be  really 
due  to  this  insect.  He  also  states  that  he  has  known  a  patient 
to  suffer  from  the  effects  of  such  a!  "  bug"  bite  for  nearly  a  year. 
Fortunately,  the  insects  are  not  very  common,  their  large  size 
and  black  color,  with  red  markings,  making  them  easily  visible 
and  readily  destroyable. 

The  largest  species  occurring  in  the  Eastern  United  States  is 
the  so-called  "wheel-bug,"  Prwiidus  cristahis,  and  this  becomes 
more  common  southwardly.  It  lays  its  curious,  jug-like  eggs  in 
hexagonal  masses  on  bark  of  trees,  fences,  or  any  other  conven- 
ient locality,  and  the  adult,  which  is  brown  in  color,  is  one  of  the 
most  readily  recognized  of  our  species.  The  thorax  has  a  semi- 
circular crest,  the  edge  of  which  is  toothed,  so  that,  viewed  from 
the  side,  it  has  somewhat  the  appearance  of  a  segment  of  a  cir- 
cular saw.     It  attacks  all  sorts  of  insects,  piercing  them  with  its 


THE    INSECT    WORLD. 


153 


powerful  beak  and  sucking  their  juices.  There  arc  other  species 
of  the  same  general  appearance  common  everywhere,  and  some 
even  maintain  themselves  in  our  cities,  feeding  upon  the  larvae 
injuring  shade-trees.  I  have  noticed  certain  of  them  in  New 
Brunswick  destroying  the  larvae  of  the  elm-leaf  beetle  in  large 

Fig.  114. 


The  wheel-bug,  Prionidus  ciistatus,  in  all  its  stages;  natural  size. 

numbers.     Taking  it  altogether,  we  find  in  this  family  mainly 
forms  that  are  beneficial  to  the  farmer. 

There  are  a  few  other  common  species,  also  predaceous  in 
character,  but  much  smaller  and  more  slender  than  the  pre- 
ceding, belonging  to  the  family  Nabidce.  Our  common  species 
of  the  genera  Nabis  and  Coriscus  are  yellowish  in  color,  flat- 
tened above  and  rather  roughened,  with  long  legs,  but  other- 
wise resembling  in  head  and  beak  the  usual  predaceous  form, 
except  that  the  beak  is  longer  and  more  slender.  They  are 
found  on  flowers  and  leaves,  preying  upon  almost  anything  that 
they  can  conquer. 


154 


AN   ECONOMIC   ENTOMOLOGY. 


A  very  curious,  chunky  little  species,  with  the  sides  of  the 
abdomen  much  elevated,  and  the  forelegs  much  broadened  and 
fitted  for  clasping,  belongs  to  the  genus  Phymata  and  the  family 
PhymatidcB.      It  is  yellow  and  brown  in  color,  and  has  the  habit 

of  placing   itself  in  the  centre   of 
Fig.  115.  certain  flowers,   in  such  a  manner 

'^^ssit^  ^^^  as   to    seem   a    part  of  the   flower 

^^.  ^  itself     It  is  thus  in  position  to  seize 

any  unlucky  insect  that  comes 
within  reach,  and,  although  it  is 
scarcely   a   quarter  of  an   inch   in 

Fig.  1x6. 


Nabh/usca. 


Phymata  erosa.—a,  b,  adult,  from   above  and 
side;  c,  front  leg;  d.  beak. 


length,  it  is  sufiiciendy  powerful  to  hold  and  conquer  even 
honey-bees.  Butterflies  are  frequently  its  victims,  and  it  is  one 
of  the  oddest  forms  in  this  order. 

We  sometimes  find  on  the  under  side  of  leaves  of  tree  and 
shrub,  little  whitish,  flat  creatures,  with  gauze-like,  broad  wing- 
covers,  and  a  broad,  gauze-like  expansion  covering  the  thorax. 
These  belong  to  the  family  TingitidcPAW^S.  are  among  the  prettiest 
species  in  the  order.  There  is  no  difficulty  in  recognizing  them 
in  the  adult  stage,  by  their  lace-like  or  reticulated  covering, 
which  is  sometimes  banded  with  brown  or  spotted.  Beneath 
this  covering  the  insects  are  black  or  brown,  and  occasionally 
they  increase  sufficiently  to  do  some  injury  to  the  plants  upon 
which  they  feed.  The  adults  usually  live  through  the  winter  and 
lay  their  eggs  in  spring  ;  but  sometimes  eggs  are  laid  in  fall,  and 
the  insects  winter  in  that  stage.  For  shelter,  fallen  leaves  are 
usually  employed,  or  the  adults  creep  under  loose  bark  scales  or 
into  crevices,  and  we  must  again  recommend  winter  work  in  clear- 


THE    INSECT    WORLD. 


155 


Fig.  117. 


ing  uj)  rubbish  of  all  kinds,  or  plowing  it  under.  Where  this  is 
done  there  will  be  no  necessity  for  active  treatment  in  summer. 
They  may  be  destroyed  at  that  time,  however,  by  the  application 
of  the  kerosene  emulsion  diluted  ten  times,  or  by  the  whale-oil 
soap  used  at  the  rate  of  one  pound  in  four  gallons  of  water. 

Perhaps  no  insect  is  better  known  than  the  "  bed-bug,"  Acan- 
thia  ledularia,  which  occurs,  especially  m  hotels,  throughout  the 
country.  It  is  wingless,  very  much  flattened,  broadly  oval  in 
shape,  and  red  brown  in  color.  It  is 
able  to  crawl  into  the  narrowest  crev- 
ices, and  no  bedstead  has  yet  been 
made  which  does  not  afford  it  shelter. 
It  is  nocturnal  in  habit,  seeking  its 
prey  at  night  and  occasionally  making 
life  miserable.  Where  a  house  be- 
comes thoroughly  infested,  specimens 
are  found  under  baseboards,  beneath 
loose  paper,  in  cracks  in  the  plaster, 
and  in  fact  wherever  there  is  an  open- 
ing large  enough  to  insert  the  blade 
of  a  thin  knife.  They  multiply  rapidly 
and  are  able  to  do  without  food  for  a 
considerable  period.      In  houses  that 

have  been  long  abandoned,  bed-bugs  of  all  sizes  may  sometimes 
be  found,  perfectly  transparent  as  if  they  had  been  always  with  • 
out  food.  It  is  probable,  therefore,  that  they  are  able  to  subsist 
upon  some  substance  other  than  human  blood.  Where  they  are 
accidentally  introduced  into  a  house  and  confined  to  beds,  there 
is  nothing  better  for  use  than  kerosene  or  gasoline.  It  should  be 
liberally  applied  in  joints,  crevices,  and  wherever  there  is  the 
least  0[)ening,  so  as  to  reach  the  bottom  before  the  material  soaks 
into  the  wood,  A  single  thorough  application  of  this  kind 
usually  proves  successful,  although  it  would  be  better  to  renew  it 
a  week  afterward,  to  reach  forms  that  have  hatched  from  eggs 
since  the  previous  application  ;  for  in  my  experience  neither 
kerosene  nor  gasoline  destroys  the  eggs  with  certainty.  Another 
effective  remedy  is  corrosive  sublimate  dissolved  in  alcohol,  and 
this  ha^  the  advantage  of  being  more  lasting,  remaining  effective 
for  some   time  after  it  is  applied.      It  is,  however,  exceedingly 


The  bed-bug,  Acanthia  lectularta. 


156  AN  ECONOMIC   ENTOMOLOGY. 

poisonous,  and  must  be  used  with  that  fact  in  mind.  Professor 
Comstock  states  that  where,  in  traveUing,  "one  is  forced  to  lodge 
at  places  infested  by  these  insects,  or  by  fleas,  protection  from 
them  can  be  had  by  sprinkling  a  small  quantity  of  pyrethrum 
powder  between  the  sheets  of  the  bed  on  retiring. ' ' 

Rather  closely  allied  to  the  bed-bug  in  structure,  if  not  in  habit, 
are  a  number  of  very  small,  flat  species,  with  fully  developed 
wing-covers,  which  are  usually  found  on  flowers,  feeding  upon  yet 
smaller  insects  and  perhaps  also  on  eggs.  They  belong  to  the 
family  Anthocorida;,  and  the  most  common  is  a  minute  black  in- 
sect with  yellow-tipped  wings,  known  as 
Fic-  1^8.  the  "insidious  flower-bug,"   Triphleps  in- 

sidiosus,  credited  with  feeding  among  others 
upon  the  insects  in  Phylloxera  galls. 

Now  follow  the  Capsidce,  containing  a 
long  series  of  species  softer  in  texture  than 
most  of  those  heretofore  described.  They 
are  plant  bugs  par  excelle^ice,  found  on 
vegetation  of  all  kinds,  frequently  in  very 
great  numbers,  and  feeding  upon  their 
juices.  The  wing- covers  are  soft  and  flex- 
„,,,,^  ,.         .,      ible  throughout,  though  thickened  basally. 

Triphleps    tiistdtosiis,    the  o  >  o    ^  j 

"  insidious  flower-bug."  They  puncture  leaf,  twig,  stem,  or  flower, 
and,  where  these  punctures  have  been 
made,  there  is  usually  a  drying  of  the  tissue  which  interrupts  the 
nourishment  of  the  plant  and  often  causes  injury.  As  a  rule,  the 
species  are  green  or  yellowish  in  color,  sometimes  black  speckled, 
and  occasionally  with  reddish  markings.  In  form  they  vary, 
being  sometimes  broadly  oval,  sometimes  quite  narrow.  The 
antennae  are  usually  long  and  prominent,  and  the  ' '  buggy' '  odor 
is  well  developed.  We  have  a  number  of  species  abundant 
enough  to  be  injurious,  and  the  question  of  dealing  with  them  is 
sometimes  complicated.  The  insects  winter  in  different  stages  ; 
often  as  an  egg  laid  in  twigs,  as  with  the  ' '  four-lined  plant-bug, ' ' 
Pcecilocapsus  lineatus,  attacking  among  others  currant  and  goose- 
berry bushes.  The  appHcation  of  insecticides  to  kill  plant-bugs 
has  been  found  unsatisfactory.  They  resist  even  the  kerosene 
emulsion  quite  strongly,  and  in  order  to  kill  adults  it  cannot  be 
diluted  more  than  five  times.     Even  agfainst  immature  forms  a 


THE    INSECT    WORLD. 


157 


very  strong  mixture  is  necessary,  and  not  more  than  six  or  seven 
parts  of  water  can  be  added  if  a  good  effect  is  expected.  In  the 
case  of  the  four-lined  bug  already  mentioned,  the  knowledge 
that  it  lays  its  eggs  near  the  tips  of  currant  and  other  twigs 
suggests  a  careful  winter  pruning,  the  cut  twigs  and  branches  to 
be  burnt,  and  in  this  way  injury  may  be  prevented  during  the 
year  following.     This  measure  is  successfully  used  where  shrubby 


Fic;.  119. 


Pacilocapsus  linealus,  four-lined  plant-bug,  natural  size  and  enlarged  :  also  egg  mass 
in  currant,  and,  at  e,  a  single  egg,  greatly  enlarged. 

or  woody  plants  are  attacked  ;  but  on  succulent  annuals,  collect- 
ing the  insects  in  the  morning,  before  they  have  become  active, 
by  shaking  them  into  some  sort  of  receptacle,  is  the  most  satis- 
factory method. 

In  the  Cotton  belt  there  was  no  more  troublesome  insect,  some 
years  ago,  than  the  "red-bug,"  or  "  cotton-stainer,"  Dysdercus 
suturellus,  so  named  from  the  fact  that  its  excrement,  voided  in 
the  opening  bolls,  stained  the  cotton  red,  and  thus  caused  it  to 
become  of  inferior  value.  Since  cotton-seed  has  become  almost 
as  valuable  as  the  cotton  itself,  and  is  now  completely  used  up, 
it  has  been  found  that  these  insects  have  become  practically  harm- 
less. It  seems  that  they  were  enabled  to  multiply  unduly  in  the 
heaps  of  decaying  cotton-seed,  and  since  at  present  no  such  heaps 
exist  they  cannot  increase  so  rapidly.  They  also  attack  oranges 
in  Florida,  and  Professor  Comstock  recommends  that  they  be 


158 


AN   ECONOMIC  ENTOMOLOGY. 


trapped  by  placing  small  heaps  of  cotton-seed  in  the  groves,  to 
attract  them  where  they  can  be  easily  destroyed  with  pure  kero- 
sene. 

Fig.  1 20. 


Dysdercus  suturelbts. — a,  pupa;  b,  adult. 

In  the  family  LygtzidcB  we  have  species  that  are  oblong  in 
shape,  rounded  behind  and  flattened  above.     They  have  quite 

long  beaks,  a  moderate- 
^^"  ^^^'  sized    head,    and    all    of 

them  are  vegetable  feed- 
ers. The  body  is  rather 
hard,  and  the  insects  are 
often  brilliantly  or  gaudily 
colored,  black  and  red, 
in  the  strongest  possible 
contrast,  being  favorite 
combinations.  Some  be- 
come nearly  an  inch  in 
length,  though  most  of 
them  are  much  smaller. 
The  best  known  of  the  species  is  the  "chinch-bug,"  Blissus 
leiccoptems,   less  than   one-fifth  of  an  inch  in  length,   blackish- 


The    chinch-bug,   Blissus    leucopterus ; 
short-winged  forms,  enlarged 


and 


n-a-»KtiRTY  OF 

Z.  p.  METCALF 


THE    INSECT   WORLD. 


159 


Fjg.  122. 


f% 


brown  in  color,  and  with  soft  white  wing-covers,  which  make  it 
quite  conspicuous.  It  feeds  on  grass  crops  of  all  kinds,  in- 
cluding grain  and  corn,  and  causes  enormous  injury  annually. 
It  can  hardly  be  said  that  we  have  any  entirely  satisfactory 
means  ol  controlling  this  pest  at  the  present  time.  Elaborate 
experiments  have  been  made  in  some  of  the  Central  States  with 
a  fungous  disease  to  which  the  insects  are  subject,  but  the  out- 
come has  hardly  equalled  expectations.  We  know  positively 
that  they  hibernate  in  the  adult  stage,  hidmg  everywhere,  and 
appearing  in  spring  to  oviposit  just  beneath  the  soil  upon  roots, 
or  on  stems  at  or  above  the  surface.  It  is  said  that  a  single 
female  lays  about  five  hundred  eggs.  The  brood  becomes  adult 
in  midsummer,  or  thereabouts,  and  there  is  then  a  tendency 
to  migrate,  particularly  if  the  original  infestation  was  in  wheat, 
which  is  by  that  time  mature  and  does  not  suit  them  as  food. 
Corn  or  any  other 
grass  crop  in  the 
vicinity  is  then  at- 
tacked, though  corn 
is  favored  because 
of  its  juiciness. 
Elaborate  publica- 
tions on  this  insect 
and  the  means  for 
its  control  have  been 
issued  by  the  United 
States  Department 
of  Agriculture,  and 

by  the  Experiment  Stations  in  Illinois,  Kansas,  and  other  States 
in  the  grain  and  corn-raising  districts  of  the  country.  The 
recommendations  generally  narrow  down  to  a  thorough  clear- 
ing up  in  winter  to  destroy  as  far  as  may  be  the  hibernating 
adults.  When  the  migrations  commence  from  wheat  to  corn, 
protection  may  often  be  obtained  by  trenching.  The  insects 
do  not  readily  resort  to  flight  even  when  adult,  but  rather  march 
from  field  to  field,  and,  by  interposing  a  trench  which  is  not 
easily  crossed,  and  where  the  insects  can  be  destroyed  by  means 
of  tar  or  kerosene,  fields  may  be  protected.  As  this  subject 
is  yet  under  consideration  by  so  many  students,  it  will  not  be 


Chinch-bug.— a,  6,  egg;  r,  newly-hatched  larva;  <?,/,  larvae 
further  advanced;  g,  pupa;  h,  leg;  i,  beak  ;  7,  tarsus. 


1 6c 


AN   ECONOMIC  ENTOMOLOGY. 


necessary  to  go  into  details  here.  The  agriculturist  in  the  regions 
subject  to  chinch-bug  attack  should  in  each  case  inform  himself 
of  what  results  have  been  reached,  and  what  recommendations 
are  made  by  the  Experiment  Station  in  his  own  State.  It  need 
only  be  added  that  the  character  of  the  weather  frequently  deter- 
mines the  increase  of  the  insects,  dry  warm  weather  favoring, 
and  wet  cold  weather  being  unfavorable  to  their  development. 

In  the  family  Coreidce  we  have  species  of  moderate  or  large 
size,  many  of  them  very  curious  in  form  and  shape,  some  of  them 
carnivorous,  but  others  vegetarian  and  more  or  less  injurious. 
They  are  oblong,  rounded  behind,  the  head  rather  small,  with 
long  antennae,  and  a  beak  of  moderate  length.  They  are  flat- 
tened above,  but  very  convex  beneath,  so  that  a  section  through 
the  insect  would  show  an  appearance  nearly  resembling  an  equi- 
lateral triangle.  The  legs  are  usually  of  moderate  length,  but 
sometimes  become  curiously  enlarged,  the  hind  legs  especially 
being  subject  to  leaf-like  expansions,  giving  the  insects  a  decidedly 
odd  and  bizarre  appearance.  They  are  brown  in  color,  some- 
times black-marked,  sometimes  with  reddish  variegations,  and 
altogether,  perhaps,  they  resemble  most  nearly  the  Reduviidcs, 
from  which  they  are  easily  distinguished  by  the  larger  head  and 
the  longer,  flattened,  four-jointed  beak.  All 
the  members  of  this  family  may  be  looked 
upon  with  suspicion,  because,  although  a 
number  of  them  do  undoubtedly  feed  upon 
other  insects,  yet  some  of  these  very  pre- 
daceous  forms  have  also  been  observed  feed- 
ing upon  plants,  and  it  is  more  than  likely 
that  they  vary  their  diet  as  occasion  serves. 
A  typical  representative  of  the  injurious 
forms  is  the  well-known  "squash-bug," 
Anasa  tristis,  which  attacks  cucurbit  vines 
of  all  kinds  and  sometimes  does  notable 
injury.  The  insect  is  dull  grayish-brown  in 
color,  the  tips  of  the  wing-covers  darker, 
while  the  edges  are  somewhat  paler.  It  is 
between  one- half  and  three-fourths  of  an  inch  in  length,  quite  a 
ready  flier,  but  with  rather  weak  legs,  and  therefore  a  poor  run- 
ner.     It  is  also  called  the  "stink-bug,"  because  of  a  peculiarly 


Fig.  123. 


The    squasli-bug 
tyisiis. 


Aiiasa 


THE    INSECT   WORLD.  l6l 

offensive  musky  odor,  which  is  quite  lasting  and  noticeable  even 
after  stained  hands  have  been  thoroughly  washed.  We  find  the 
adult  late  in  fall,  and  it  remains  in  that  condition  during  the  winter, 
under  bark  of  trees,  under  rubbish,  in  barns  and  similar  localities. 
A  large  number  are  destroyed  by  one  cause  or  another  during  this 
period,  but  some  survive,  and  in  the  spring  lay  upon  the  squash 
or  other  cucurbit  vines  patches  of  unusually  large,  almost  golden- 
brown  eggs.  The  little  fellows  that  hatch  from  them  are  much 
shorter  and  broader  in  proportion  than  the  adults,  maturing  some 
time  during  midsummer,  and  providing  thus  for  a  second  genera- 
tion. Only  two  broods  occur  in  the  Middle  States,  though  they 
overlap  somewhat,  making  it  appear  as  if  breeding  continued 
during  the  entire  summer  and  early  fall.  The  punctures  made  by 
this  insect  in  feeding  seem  to  have  a  peculiarly  poisonous  effect 
upon  the  plants,  young  vines  especially  being  apt  to  succumb  to 
even  a  few  specimens.  This  is  another  of  the  cases  where  clean- 
liness becomes  advantageous,  and  constitutes  also  a  method  of 
avoiding  injury  to  a  great  extent.  It  has  been  found  that  the 
second  brood  does  not  mature  until  quite  late  in  fall,  and,  seem- 
ingly, only  those  that  become  adult  after  the  beginning  of  Sep- 
tember have  any  tendency  to  go  into  winter  quarters.  It  should 
be  the  object  of  every  grower  afflicted  by  these  insects  to  destroy 
the  cucurbit  vines  just  as  soon  as  he  has  all  the  crop  he  wants  from 
them.  This  can  be  done  by  plowing  under  thoroughly,  or  by 
raking  out  and  burning  the  vines.  In  either  case  the  immature 
bugs  starve  to  death  and  never  develop  into  adults.  If  this  practice 
is  followed  by  all  growers,  in  localities  where  raising  cucurbits  is 
an  industry,  there  is  little  danger  of  trouble  from  the  insects.  In 
kitchen  gardens,  and  on  a  small  scale,  injury  may  be  prevented 
by  first  picking  off  the  bugs  wherever  they  are  noticed  and,  later, 
picking  off  those  parts  of  the  leaves  containing  eggs.  The  eggs 
are  laid  on  the  under  side,  and  are  so  prominent  that  looking  for 
them  is  a  matter  of  little  difficulty,  no  cluster  escaping  a  more 
than  casual  glance. 

Now  comes  a  series  of  broad,  heavily-built  bugs,  in  which  the 
scutellum  is  greatly  elongated  and  covers  a  large  part  of  the 
abdomen.  In  this,  the  PentatomidcB ,  the  enlarged  scutellum  is 
triangular,  and  has  a  lateral  groove  into  which  the  edges  of  the 
wing-covers  fit  when  not  in  use.     Here  also  we  have  some  species 

II 


l62 


AN  ECONOMIC  ENTOMOLOGY. 


that  are  predaceous  and  others  that  are  plant-feeders,  and,  as  in 
the  preceding  case,  it  is  difficult  to  say  always  whether  the 
species  are  beneficial  or  injurious.  They  will  all  stand  watching, 
at  any  rate,  but,  fortunately,  not  many  of  them  occur  in  great 
numbers.  Perhaps  the  most  marked  exception  is  the  ' '  harlequin 
cabbage-bug,"  Murgantia  histrionica.  This  is  one  of  the  most 
serious  pests  to  cabbage  in  the  Southern  States,  being  found  in 

small     numbers    on    Long 
Fig.  124.  Island,  in  the  southern  part 

of  New  Jersey,  and  then 
increasing  rapidly  in  num- 
ber and  destructiveness 
throughout  the  South  and 
Southwest.  These  also  win- 
ter in  the  adult  stage,  and 
egg-laying  begins  quite 
early  in  the  spring.  They 
are  said  to  pass  through  all 
their  stages  in  two  weeks, 
and  it  can  be  readily  seen 
that  there  is  room  for  a 
number  of  generations  in 
the  course  of  the  season.  Practical  experiments  seem  to  prove 
that  fighting  the  adults  early  in  spring  is  most  effective.  Mus- 
tard seems  to  be  their  favorite  food-plant,  and  it  is  recommended 
to  plant  rows  of  mustard  between  the  cabbage  rows  for  the  pur- 
pose of  attracting  the  old  bugs.  They  can  be  sprayed  there 
with  pure  kerosene,  which  kills  them  readily,  and  if  it  also  kills 
the  mustard,  no  great  harm  is  done  ;  or,  they  can  be  collected  in 
pans  in  the  morning,  before  they  have  become  active,  and  in  this 
way  they  will  be  sufficiently  reduced  in  number  to  prevent  them 
from  becoming  troublesome  later  on.  Of  course  this  is  another 
of  the  remedies  that  depends  for  its  greatest  success  upon  com- 
bined action.  It  has  also  been  recommended  that  the  hibernating 
bugs  be  trapped  in  early  spring  under  turnip  or  cabbage  leaves, 
preserved  for  that  purpose  during  the  winter. 

The  allied  family  Cydnidce  is  interesting,  having  the  legs  formed 
for  digging,  though  otherwise  resembling  the  preceding.  Their 
food  habits  are  not  well  known  ;  but  none  of  them  are  mjurious. 


/  9 

Harlequin  cabbage-bug,  Alurganlia  hhlyion- 
ica. — (7,  b,  larva  and  pupa  ;  c,  d,  e,  eggs,  natural 
sizeand  enlarged,  from  side  and  top  ,/,g',  adult. 


THE    INSECT    WORLD.  163 

A  very  curious  series  is  the  Corimelcenida,  or  "negro-bugs," 
distinct  by  their  usually  small  size,   their  intense   black   colors, 
which    occasionally   have   a   bluish    or  greenish 
tinge,    and    by   their  very  convex   form.      The 
scutellum  covers  nearly  the  entire  upper  surface 
of  the  botly,  and  the  insects  are  quite  generally 
mistaken  for  small  beetles.     They  may  be  found 
on  plants  of  all  kinds  and  sometimes  in  consider- 
able numbers,  but  noticeable  injury  is  rarely  in- 
flicted.    Their  most  disagreeable  habit  is  laying      Fiea-iike  negro- 
eggs  on  a  number  of  the  small  fruits,  like  black-   ^'f.'     ^'^''"f^"^ 

^°  _  '  ^;</;ca>ia, enlarged. 

berry  and  raspberry,  and  if  these   are   crushed 

in   eating,  an   excessively  disagreeable,    ' '  bed-buggy' '   taste   is 

noticed. 

The  last  family  of  this  order  to  which  we  call  attention,  even 
though  it  is  not  injurious,  is  the  ScutelleridcB,  the  species  of 
which  are  yet  more  oval,  though  perhaps  less  convex  than  the 
preceding.  As  before,  the  scutellum  covers  nearly  the  whole 
of  the  abdomen,  but  these  species  are  often  brightly  colored. 
They  are  moderate  in  size  or  quite  large,  and  are  southern  and 
western,  a  few  species  only  being  rarely  found  northward. 

Taking  it  altogether  we  have  in  the  heteropterous  series  of  the 
Hemiptera  forms  which  gain  their  food  by  sucking  juices,  and  in 
perhaps  the  majority  of  instances  the  juices  of  plants.  Yet, 
taking  it  altogether,  there  are  comparatively  few  seriously  injuri- 
ous species,  and,  if  we  except  the  "chinch-bug,"  they  do  not 
begin  to  compare  with  their  homopterous  brethren  in  the  amount 
of  injury  they  do  to  farm  crops.  The  insects  are  nearly  all  diffi- 
cult to  deal  with,  as  they  resist  insecticides  quite  strongly.  No 
weak  mixtures  affect  them,  and  even  the  kerosene  emulsion 
cannot  be  diluted  more  than  three  or  four  times,  if  any  large 
proportion  of  adults  are  to  be  killed.  Stomach  poisons  are  out 
of  the  question,  of  course,  and  we  are  thus  reduced  to  mechani- 
cal means  or  farm  practice  to  avoid  trouble.  These  methods 
have  been  indicated  in  the  course  of  the  chapter,  and  need  no 
formal  repetition. 


164 


AN  ECONOMIC  ENTOMOLOGY. 


CHAPTER    VI. 


THE  COLEOPTERA  OR  BEETLES. 


Fig.  126. 


The  Coleoptera,  "horn-winged"  insects,  or  beetles,  are  dis- 
tinguished by  the  hard,  horny,  or  tough,  leathery  texture  of  the 
fore-wings  or  elytra,  which  meet  in  a  straight  line  down  the 
middle  of  the  back,  and  are  not  used  in  flight,  serving  as  wing- 
covers  only.  They  vary  greatly,  and  are  numerous  in  specimens 
and  species,  over  twelve  thousand  kinds  having  been  described 
from  the  United  States  and  British  America  alone.  They  are  as 
diverse  in  habit  as  in  size  and  form,  some  being  among  the  most 
dangerous  enemies  of  agriculture,  while  others  are  among  the 
most  useful. 

It  seems  at  first  sight  as  if  the  recognition  of  beneficial  or  in- 
jurious forms  among  so  many  would  prove  a  hopeless  task,  and 
yet  we  find  it  in  most  cases  possible  to  say  at  a  glance  whether  a 
given  specimen  is  herbivorous,  i.e.,  plant- 
feeding,  or  carnivo7'oiis,  i.e.,  flesh-feeding 
and  predaceous. 

All  beetles  are  mandibulate  and  chew  their 
food  ;  but  in  one  series  the  head  is  more  or 
less  prolonged  into  a  snout  or  beak,  at  the 
end  of  which  the  much-reduced  mouth  parts 
are  situated.     These  are  the  Rhynchophora, 
or  "snout-beetles,"  all  of  which  are  plant- 
feeders  and  injurious,  or  likely  to  prove  so. 
The  true  Coleoptera,  in  which  the  head  is 
h,  normally  four-jointed;   not  prolonged  iuto  a  beak,  wc  Can  separate 
c   four-jointed,  with  the  |     ^j^^  structure  of  the  tarsi  or  feet.     Nor- 

third  joint  deeply  lobed,        ■' 

from  side  and  from  above,  mally  there  are  fivc  joiuts  or  segments  to 
each  pair  of  feet ;  but  there  are  many  de- 
partures from  this  rule,  one  large  series  having  four  apparent 
joints  only,  of  which  the  third  is  lobed  or  deeply  notched.  The 
species  in  which  this  structure  obtains  are  all  plant-feeders  ; 
either  on  leaves  or  in  stems,  trunks,  branches,  or  roots  ;  often 
in  dead,  though  more  usually  in  living  tissue.     In  no  other  case 


Tarsi    in  Coleoptera 
a,  normally   five-jointed 


THE    INSECT    WORLD.  1 65 

is  the  structure  df  the  tarsi  alone  an  absolute  guide  to  the  food 
habits  ;  but  if  we  turn  to  the  antennae  or  feelers  we  obtain  an 
additional  basis. 

Roughly  speaking,  the  beetles,  other  than  those  already  sepa- 
rated off,  may  be  divided  into  filicornia,  or  those  in  which  the 
antennae  are  more  or  less  thread-like,  and  which  are  usually  car- 
nivorous ;  clavicornia,  in  which  they  enlarge  toward  the  tip  or 
terminate  in  a  more  or  less  marked  club,  which  are  rarely  carniv- 
orous and  usually  scavengers  ;  serricornia,  where  the  joints  are 
somewhat  flattened  and  widen  toward  the  tip,  so  that  one  mar- 
gin resembles  to  a  greater  or  less  degree  the  toothed  edge  of  a 
saw,  which  are  feeders  upon  vegetation,  as  a  rule ;  lamelli- 
cornia,  in  which  there  is  a  leaf-like  club  at  tip,  which  are  always 
vegetable  feeders  ;  and  vio7iilicornia,  where  the  joints  are  more 
or  less  oval  or  globular  and  set  so  as  to  appear  like  a  string  of 
beads. 

The  terms  Jilicornia  and  vionilicornia  are  not  in  general  use  at 
the  present  time.  The  latter  series  has  the  hind  tarsi  four-jointed 
and  the  anterior  and  middle  five-jointed,  whence  they  are  now 
termed  Heteromcra,  or  "different-jointed,"  to  distinguish  them 
from  the  "'  Isomera''  where  all  feet  have  the  same  number  of 
segments.  But  they  are  not  uniform  in  habit,  so  that  the  deter- 
mination of  an  insect  as  belonging  to  this  heteromerous  series 
does  not  at  once  determine  whether  it  is  friend  or  foe.  For  the 
Jilicornia  the  term  Adephaga  is  used,  from  the  usually  predaceous 
habits. 

Following  the  usual  order  of  systematic  arrangement,  a  com- 
prehensive statement  of  the  differences  is  as  follows  : 

I.  Series  with  the  head  not  prolonged  into  a  snout,       true  Coleopter.a. 

«,  The  antennae  filiform,  or  thread-like,  the  tarsi  with  five  joints  on 

all  feet Adephaga. 

b.  The  antennae  thickening  outwardly  into  a  more  or  less  well-formed 

club,  tarsi  with  an  equal  though  varying  number  of  joints  on 
all  feet Clavicornia. 

c,  The  antennae  serrate   or  saw-toothed,    the    tarsi    usually    five- 

jointed     Serricornia. 

d,  The  antennae  with  a  lamellate  or  leaf-like  club  at  tip,  the  tarsi 

five-jointed Lamellicornia. 

e.  The  antennae  somewhat  variable,  the  tarsi  four-jointed,  the  third 

deeply  lobed  or  cleft Phvtophaga. 


1 66  ^A'   ECONOMIC  ENTOMOLOGY. 

',  Theanteniice  variable,  though  usually  moniliform  ;  fore  and  middle 

tarsi  five-jointed,  hind  tarsi  four-jointed   ....  Heteromera. 

2.  Series  with  the  head  prolonged  into  a  more  or  less  prominent  snout,. 

hence  called  snout-beetles  or  weevils Rhynchophora. 

In  the  Adephaga  there  are  many  species  of  predaceous  habit 
in  the  larval  as  well  as  adult  stage,  of  which  a  few  more  common 
types  may  serve  as  examples. 

The  ' '  tiger-beetles, ' '  or  Cicmdelidce ^  are  moderately  large, 
very  active  and  graceful  species,  that  run  rapidly  and  fly  readily. 
Most  of  them  frequent  sandy  or  open  spaces,  their  colors  often 
matching  their  surroundings  with  marvellous  accuracy.  On  the 
seashore  they  are  white,  or  gray  with  white  hairs  and  lines,  and 
on  the  marshes  or  mud-flats  the  prevailing  colors  are  dull  mouse- 
gray,  without  contrasting  lines.  Early  in  spring  a  bright-green 
species  is  foimd  at  the  margin  of  woods  or  in  shaded  lanes,  promi- 
nent on  the  bare  ground  for  an  instant,  but  lost  to  sight  at  once, 
when  startled,  in  a  tuft  of  grass  or  on  a  moss-covered  stone  or 
log. 

The  larvae  are  uncouth  creatures,  rarely  seen  unless  sought  for. 
They  make  vertical  burrows  in  sandy  soil  or  along  roads,  and 
there  wait  for  passing  prey,  their  round  flat  head  closing  the 
opening  completely,  while  their  eyes  are  so  set  as  to  command 
the  near  surroundings.  They  are  humped  posteriorly,  and  on 
the  hump  curved  spines  are  set,  which  may  be  forced  into  the 
burrow  wall  to  maintain  a  position  at  any  height,  and  to  resist 
without  effort  any  ordinary  attempt  to  pull  them  out  of  their  den. 
Though  these  "tigers"  are  exceedingly  voracious,  they  are  of 
little  benefit  to  the  agriculturist,  because  they  do  not  frequent 
cultivated  fields  or  orchards. 

The  Carabidce,  or  "ground-beetles,"  run  to  black  and  brown 
colors  without  prominent  markings,  and  are  usually  more  or  less 
flattened.  They  live  under  stones,  sticks,  leaves,  or  shelter  of 
any  kind,  in  fields  and  along  the  edges  of  woods,  more  rarely  in 
the  woods  themselves,  and  sometimes  under  loose  bark  or  even 
among  leaves.  They  are  of  a  retiring  disposition,  and  seldom 
stir  abroad  until  after  dark,  when  the  majority  fly  readily.  Many 
of  them  are  attracted  to  light,  and  are  recognizable,  when  they 
strike  the  table  or  other  flat  surface,  by  the  rapidity  with  which 
they  run,  by  their  prominent  mandibles,  and  slender,  moderately- 


Fig.  T29. 


Fig.  133. 


Fig.  130. 


Fig.  135. 


A®   ^Iml}  j& 

Fig.  134.  Fig.  136. 


Tiger-beetles  and  ground-beetles. — Fig.  127,  larva  of  Ctctndela.  Fig.  128,  head  of 
Cicindela,  to  show  mandible.  Fig.  129,  C.  generosa.  Fig.  130,  C.  purp7trea.  Fig.  131, 
C.  sexgiittala.  Fig.  132,  C.  rcpanda.  Fig.  133,  Calosoma  cahditm  and  its  larva.  Fig.  134, 
C.  scrutator.  Fig.  135,  Brachiniis  fumans.  Fig.  12,6,  Harpaliis  caliginosus.  Fig.  137, 
larva  of  Harpalus,  devouring  larva  of  plum-curculio.  Fig.  13S,  Lebia  grandis.  All 
except  Fig.  135  about  natural  size. 

167 


1 68  AN  ECONOMIC  ENTOMOLOGY. 

long  antennae.  Some  of  them  are  dirty  clay-yellow  in  color,  with 
the  disk  of  the  wing-covers  marked  with  black  or  brown. 

We  have  only  a  few  species  belonging  to  the  genera  Carabus 
and  Calosoma,  in  marked  contrast  to  the  great  number  found  in 
European  fields,  none  of  our  large  forms  having  found  life  in 
tilled  land  tolerable.  The  species  of  Calosoma  often  ascend  trees 
and  feed  on  caterpillars,  the  term  "caterpillar  hunters"  having 
been  in  consequence  applied  to  them  ;  but  some  of  the  smaller 
species  also  have  similar  habits.  In  orchards  they  are  sometimes 
found  hidden  just  beneath  the  surface  of  the  soil,  close  to  the  base 
of  the  trees. 

The  ' '  Bombardier  beetles, ' '  belonging  to  the  genus  Brachinus, 
may  be  especially  mentioned  because  of  their  peculiar  power  of 
emitting  a  puff  of  bluish  vapor  from  the  anus  when  suddenly  dis- 
turbed. They  have  the  body,  head,  and  thorax  reddish,  the 
elytra  blue,  and  are  found  under  stones  along  the  edges  of  roads 
and  near  woodlands,  or,  more  rarely,  in  the  loose  rubbish  at  the 
base  of  trees. 

A  series  of  very  much  flattened  species  frequents  flowers,  feeding 
upon  the  minute  insects  abundant  there,  and  these  are  sometimes 
red  and  blue,  or  even  brilliant  metallic  green,  with  the  wing- 
covers  squarely  cut  ofl  behind  so  as  to  expose  the  tip  of  the 
abdomen.  Among  these  is  the  Lebia  grandis,  a  moderate-sized 
species,  with  yellowish-red  head  and  thorax,  and  blue  elytra,  that 
makes  itself  useful  by  feeding  upon  the  eggs  and  larvae  of  the 
Colorado  potato-beetle. 

But  the  great  majority  of  our  species  are  moderate  in  size,  and 
of  powerful  build,  black  or  nearly  so,  lurking  under  all  sorts  of 
rubbish  in  field  and  orchard,  frequently  in  large  numbers,  yet 
rarely  observed,  and  ready  at  all  times  to  pounce  upon  any  soft- 
bodied  larvae  that  come  within  their  range  of  vision.  These 
belong  to  the  genera  Pterostichus,  Anisodactyhcs,  Amara,  Har- 
palus,  Agonodenis,  or  their  close  allies,  and  they  are  decidedly 
important  factors  in  checking  the  undue  increase  of  certain  species 
which  must  go  underground  to  complete  their  transformations, 
— e.g.,\.\\e  "  plum-curculio,"  "  pear-midge,"  and  others.-  Their 
larvae  are  even  more  retiring  and  less  frequently  seen,  but  live 
in  similar  situations.  They  are  slender,  more  or  less  flattened, 
of  nearly  equal  width,  with  six  short  legs,  a  pair  of  prominent 


THE    INSECT   WORLD. 


169 


mandibles,  and  a  pair  of  bristly  processes  at  the  anal  end  of  the 
body. 

Two  other  families  belonj^ing  to  the  Adephaga  are  aquatic  in 
the  larval  as  well  as  adult  stage,  and  are  as  predaceous  as  their 
terrestrial       relatives. 

The    Dytiscidce     and  ^^"'-  ^^9- 

their  larvae  have  been 
termed  "water- 
tigers,"  and  the  larger 
species  attack  small 
fish  as  well  as  insects. 
In  form  they  are  oval 
and  somewhat  flat- 
tened, and  they  may 
often  be  seen  rising  to 
the  surface  of  quiet 
pools  or  spring-holes, 
head  down,  releasing 
a  bubble  of  air,  and 
then,  after  remaining 
for  a  little  time,  with 

the       anal       extremity  a  water-tiger,  ZJy/w^j  wrtr^/wa/«. — a,  larva,  devour- 

,                    ,                   ^  ing  an  Agrion  larva  ;  i,  pupa  ;  c,  male  beetle,  the  elytra 

aDOVe        tne       SUriace,  of  the  female  at  side  ;  rf,  anterior  tarsus  of  the  male,  with 

again    starting    for    the  sucking  disks;   e,  tarsus  of  the  female:  a,  b,  c,  about 

t      ^.              rr^x           •  natural  size. 

bottom.  1  here  is  con- 
siderable space  between  the  wing-covers  and  the  abdomen  in 
these  species,  and  this  is  utilized  as  a  reservoir  for  the  air  which 
the  insect  breathes  beneath  the  surface.  When  it  becomes  impure 
the  beetle  rises  again  to  the  surface,  releases  the  vitiated  air,  and 
takes  in  a  new  supply. 

This  ends  the  series  Adephaga^  and  no  practically  injurious 
forms  exist  in  it  ;  all  are  more  or  less  beneficial  by  reason  of  their 
predaceous  habits.  Under  some  circumstances  a  few  of  the 
species  eat  pollen,  and  after  midsummer  some  have  been  found 
gnawing  grass-seed  ;  one  or  two  species  have  even  been  found 
eating  into  the  kernels  of  corn,  so  there  appears  to  be  a  tendency 
to  vary  to  a  vegetable  diet  under  certain  conditions.  In  fact  it 
has  been  demonstrated  that  in  many  species  some  vegetable 
matter  is  regularly  eaten  ;  yet,  as  this  feeding  is  not  of  a  character 


170 


JiV   ECONOMIC    ENTOMOLOGY. 


injurious   to  the  agriculturist,  the   series    may  be,   as   a  whole, 
accounted  beneficial. 

In  the  Clavicornia  we  have  a  much  greater  diversity  of  form, 
and  many  families,  diftering  widely  in  habit,  and  some  of  these  are 
economically  important. 

Fig.   140. 


A  water-scavenger,  Hydrophilus  triangularis. — a,  llie  larva  ;  b,  male  adult  ;  c,  pupa  ;  d, 
opened,  and  e,  closed  egg  case  ;  y  to  i,  enlarged  structural  details  of  the  adult. 

First,  joining  to  the  aquatic  Adephaga  there  are  two  families 
of  aquatic  Clavicornia,  the  Hydrophilidce.  or  "  water-scavengers," 
and  the  Gyrinidce,  or  "whirligig-beetles." 
The  former  resemble  the  water-tigers  in 
general  appearance,  but  are  more  convex 
above  and  more  flattened  below,  usually  with 
brightly-polished  wing-covers.  The  differ- 
ence in  the  form  of  the  antennae  will  easily 
prevent  confusing  the  families. 

The  Gyrinidce  cannot  be  mistaken.     They 
are  black  or  bronzed,  oval,  shining,  with  un- 
usually long  forelegs,  and  disport  themselves 
ifhiriigig-'-beetie    i"  swamis  OH  the  surfacc  of  ponds  and  streams, 
(1)  and  its  larva  (2):  nat-    darting  here  and  there,  or  sometimes  swim- 

ural  size.  •  •  11        •        1  11  1 

ming  rapidly  in  large  or  small,  regular  or 
irregular  circles,  whence  they  derive  their  "whirligig"  appella- 
tion. They  are  predaceous  in  all  stages,  but  of  no  agricultural 
value  from  their  strictly  aquatic  habits. 


rilK    IXSECT   WORLD. 


171 


The  family  Si7p/iiiia\  containing  what  are  popularly  known  as 
"carrion"  and  "burying  beetles,"  is  in  sharp  contrast  to  any- 
thing heretofore  spoken  of,  and  here  the  antennce  are  capitate, — 
i.e.,  terminated  by  a  spherical  or  ovate  knob  abruptly  formed, 
like  a  head.  The  beetles  are  usually  found  on  or  about  carrion 
of  all  kinds,  though  some  of  the  smaller  forms  live  in  decaying 
fungi.  In  the  large  species  there  are  two  distinct  types,  repre- 
sented on  the  one  hand  by  the  genus  Silpha,  in  which  the  species 

Fig.  142. 


Carrion  beetles. — a,  Necrophorus  americana ;  b,  larva  oi  Silpha  lapponica  ;  c,  Silpka 

americana. 


are  much  flattened  and  proportionately  very  broad,  with  small 
heads,  and  on  the  other  by  the  genus  Necrophorus,  in  which  the 
species  are  much  more  heavily  built,  narrower,  not  flattened,  and 
with  large  heads.  These  are  the  true  "burying"  beetles,  and 
derive  the  name  from  their  habit  of  excavating  beneath  small 
dead  animals  and  gradually  sinking  them  below  the  surface  level. 
Then  the  females  lay  their  eggs  in  and  the  larvae  live  upon  the 
buried  and  decaying  creatures.  The  other  carrion  beetles  make 
no  pretence  of  burying  their  prey,  but  lay  their  eggs  at  once, 
and  the  larvae  feed  upon  it  from  below,  usually  making  a  short 
burrow  in  the  soil  for  shelter,  though  this  is  not  universal.  In 
both  types  the  larvae  are  black,  flattened,  broadly  oval,  and  with 


172 


AN  ECONOMIC  ENTOMOLOGY. 


Fig.  143. 


Rove-beetle  and  its  larva. 


the  segments  distinctly  marked  at  the  edges.  These  beetles  have 
the  sense  of  smell  wonderfully  developed,  and  I  have  frequently 
covered  a  small,  freshly-killed  animal  with  a  box  of  wood  or 
tin,  only  to  find  next  morning  a  number  of  the  insects  beneath 
it.  The  species  are  generally  nocturnal,  and  as  scavengers  are 
useful,  or  at  least  innoxious. 

The  large  series  of  "rove-beetles,"  or  Staphylinidce,  is  pecu- 
liar in  the  short  wing-covers,  which  leave  more  than  half  the 
abdomen  exposed.  The  species  are  always 
long  and  comparatively  narrow,  usually 
with  a  large  head  and  well-developed  man- 
dibles, and  live  in  all  sorts  of  fermenting, 
^  decaying,  or  excrementitious  animal  or 
vegetable  matter.  Most  of  them  are  small, 
and  many  are  found  beneath  bark,  in  fer- 
menting sap,  or  in  fungi,  while  the  larger 
forms  are  often  found  in  or  under  animal 
excrement,  or  on  or  under  carrion.  In 
short,  the  species  are  scavengers,  with  a 
tendency  to  a  predatory  habit  in  some  cases,  and  never  any 
disposition  to  feed  upon  growing  vegetation.  They  may  thus  be 
accounted  either  actively  beneficial  or  at  least  not  injurious,  and 
as  scavengers  they  aid  in  reducing  organic  matter  into  condition 
for  assimilation  by  plant-life. 

The  next  family  meriting  attention  from  its  economic  interest 
is  the  Coccinellidce,  or,  as  the  species  are  commonly  termed, 
"lady-bugs"  or  "lady-birds."  Scientifically  these  insects  are 
distinguished  by  having  the  tarsi  three-jointed  only  ;  but  practi- 
cally they  are  recognizable  by  their  oval  or  round  form, — always 
convex,  sometimes  almost  hemispherical,  — and  by  their  colors, 
which  are  either  of  some  shade  of  red  with  black  spots  and 
markings,  or  black,  with  red  or  yellow  spots.  The  species  are 
never  large,  sometimes  very  small  ;  but  in  almost  all  cases  are 
predaceous,  their  prey  consisting  chiefly  of  plant-lice  or  scale 
insects.  The  larvae,  which  have  the  same  feeding  habits,  are 
usually  fusiform,  with  a  small  head  and  quite  long  legs.  They 
are  often  prettily  colored,  sometimes  with  spiny  warts  or  pro- 
cesses, and  may  be  seen  running  about  wherever  plant-lice 
abound.     Patches  of  from   fifteen   to   forty  of  the  yellow  eggs 


THE    INSECT   WORLD. 


173 


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174 


AN   ECONOMIC    ENTOMOLOGY. 


laid  by  the  beetles  are  often  seen  in  abundance  on  infested 
plants. 

The  species  of  Mcgilla  and  Hippodamia  are  more  oval  and 
less  convex  than  usual,  and  some  of  them  have  been  found  feed- 
ing on  pollen  or  even  seeds,  when  their  natural  prey  was  scarce  ; 
yet  I  have  observed  these  same  species  doing  yeoman's  work  in 
the  destruction  of  plant-lice  on  melon-vines. 

The  generai  Ada/ia  and  Coccinella  contain  the  more  hemispher- 
ical types,  and  among  the  most  common  are  the  "  9-spotted  lady- 
bird," Coccinella  g-?iotata,  which  is  one  of  the  larger  species,  and 
the  "  2-spotted  lady-bird,"  Adalia  bipzincta,  which  is  the  smaller 
and  perhaps  most  frequently  seen  in  gardens  and  even  houses. 
Among  the  largest  of  our  forms  is  the  "  15-spotted  lady-bird," 
Anatis  i_^ -punctata,  interesting  from  its  color  variations,  ranging 
from  creamy-white  with  distinct  black  spots  to  uniform  mahogany 
brown. 

Opening  quite  a  distinct  series  of  species,  which  are  black, 
with  red  or  yellow  spots,  is  the  "  twice-stabbed"  lady-bird,  Chilo- 
coriis  bivulnerus,  in  which  the  larva  is  spiny.  This  is  black, 
almost  hemispherical,  with  a  somewhat  ovate  red  spot  on  each 
wing-cover,  and  is  found  throughout  the  United  States.  Its 
chief  food,  in  the  larval  as  well  as  the  adult  stage,  consists  of  scale 
insects,  and  it  is  one  of  the  most  effective  checks  on  that  kind  of 
plant  pest,  under  favorable  circumstances  ridding  individual  trees 
completely. 

We  have  other  similar  but  smaller  species,  sometimes  with 
numerous  yellow  spots  on  the  wing-covers,  and  most  of  them 
have  the  scale-eating  habit  to  a  greater  or  less  extent.  The 
species  of  Peiitilia  are  uniformly  black  and  very  small,  less  in 
size  than  most  of  the  scale  insects  upon  which  they  prey  ;  but 
they,  as  well  as  their  minute  spiny  larvae,  are  great  feeders,  espe- 
cially upon  the  eggs  and  larvae.  The  destructive  San  Jose  scale 
has  no  more  persistent  or  effective  enemy  than  this  kind  of  small 
lady-bird. 

The  species  of  Scymnns  are  also  small,  usually  recognizable  by 
their  fine  pubescent  or  hairy  clothing  and  black  colors.  There 
is  a  tendency  to  red-tipped  wing-covers  or  red  thorax,  and  these 
forms  also  prey  largely  upon  scales.  To  this  family  belong  the 
Australian  species  of  Vedalia,  Orciis,  and  Rhizobius,  introduced 


THE    INSECT   WORLD. 


175 


Fig.  150. 


to  destroy  the  also  imported  "cottony  cushion-scale,"  leery  a 
piirchasi.  The  relation  of  these  species  has  been  already  dis- 
cussed when  speaking  of  the  scale, 
and  will  be  again  referred  to  in  Part 
III.  of  this  work. 

There  are  few  rules  without  excep- 
tions, and  so  we  find  sinners  among 
the  lady-birds  also, — all  belonging  to 
the  genus  Epilachne.  The  species 
are  large,  hemispherical,  and  yellow, 
with  black  spots.  The  larvae  are 
also  yellow,  elongate  oval,  with  long 
branched  spines.  E.  borealis  is  the 
Northern  and  Eastern  species  at- 
tacking cucumber,  melon,  and  sim- 
ilar vines,  while  E.  comipta  is  found 
in  the  West  and  Southwest,  injuring 
beans.  A  curious  feature  in  E.  borealis 
is  the  manner  in  which  the  adult 
marks  out  a  circle  at  the  edge  of  a 
leaf  and  feeds  within  it  until  all  usable 
tissue  is  exhausted,  before  proceeding 
to  another  place  to  repeat  the  opera- 
tion. 

As  these  injurious  species  feed 
openly  in  all  stages,  they  can  be 
reached  without  trouble  by  any  of  the 
arsenites. 

The  family  Erotylida;  contains  some 
very  prettily  marked  species  of  quite 
diverse  forms,  most  of  which  feed  in 
or  on  fungi,  or  may  be  found  under 
loose  bark,  and  are,  therefore,  innox- 
ious. In  the  genus  Languria,  how- 
ever, we  find  an  exception,  since  their 
larvae  live  in  the  stems  of  clover  and 
other  plants.  They  are  very  slender, 
almost  cylindrical,  from  one-fourth  to 
one-half  an  inch  in  length,  and  have  the  wing-covers  blue  or 


Epilachne  comipta. — A,  adult  ; 
B,  pupa;  C,  larva;  1),  injury  on 
bean. 


176 


AN   ECONOMIC   ENTOMOLOGY. 


black,  while  the  thorax  is  usually  more  or  less  red  or  yellow. 
Our  common  clover-feeding  species  is  L.  mozardi.  It  is  rarely 
that  any  species  becomes  abundant  enough  to  do  noticeable  in- 

FiG.  151. 


Languria  mozardi. — n,  egg  ;  b,  larva  in  clover  stem  ;  c,  larva  ;  d,  pupa  ;  e,  adult. 

jury  ;  but  in  clover,  if  a  sufficiently  large  infested  area  occurs, 
prompt  close  cutting  or  turning  under  the  sod  will  be  most 
effective  in  checking  present  and  preventing  future  injury. 

The  Cucujidcz  are  elongate  and  very  much  flattened  beetles, 
fitted  to  live  under  bark  of  trees  or  in  the  narrow  crevices  where 


Silvanus  surinatnensis . — a,  beetle  ;  b,  pupa  ;  c,  larva. 

they  are  usually  found.      Some  of  the  species  of  Silvanus,  notably 
6^.  siirinamensis,  a  brown  species,  hardly  more  than  one-eighth 


THE    INSECT   WORLD. 


177 


inch  in  length,  with  the  edges  of  the  thorax  toothed,  are  excep- 
tions in  habit,  though  not  in  form,  and  often  infest  granaries, 
mills,  and  stables.  The  adult  as  well  as  its  larva  is  frequently- 
found  in  mangers  or  in  neglected  little  masses  of  meal,  flour,  or 
grain,  in  which  they  breed.  Cleanliness  is  the  best  remedy  when 
these  insects  become  abundant  :  allow  no  partly  emptied  boxes 
or  bags  to  lie  about,  keep  current  supplies  covered  or  tied  up, 
and  sweep  out  corners  at  short  intervals.  Bisulphide  of  carbon, 
where  its  apjilication  is  possible,  is  an  effective  remedy,  readily- 
destroying  the  beetles  as  well  as  their  larvae. 


Fig.  153. 


Fig.  154. 


Fig.  155. 


Atomaria  cphippiata. 


Cotticaria  pumila. 


Cryptophagtis  croccus. 


There  are  other,  yet  smaller  beetles  found  in  similar  situations 
in  less  numbers,  and  these  belong  to  allied  families.  They  may- 
be brown,  not  more  than  one-sixteenth  of  an  inch  in  length,  with 
an  oval  body  and  narrow  thorax,  and  then  they  are  probably 
species  of  Corticaria  ;  they  may  be  of  similar  color,  but  with  the 
thorax  and  body  more  nearly  of  a  width,  and  then  they  may 
belong  io  Ato)fiaria  or  Cryptophagiis ;  or  they  may  be  equally 
minute  but  flattened,  black,  with  red  or  yellow  spots  or  bands  on 
the  elytra,  and  then  they  probably  belong  to  Litargus.  All  may 
be  treated  as  above  suggested. 

We  have  a  series  of  robust,  small  or  moderate- sized  beetles, 
usually  broad  but  sometimes  narrowly  oval,  with  small  retracted 
head,  slender,  moderately  long  legs,  capable  of  being  so  closely 
folded  upon  the  breast  as  to  be  almost  invisible,  and  with  the 
unpleasant  habit  of  feeding  upon  dried  animal  substances,  such 
as  furs,  skins,  woollens,  museum  specimens,  meats,  and  the  like. 

12 


178 


AN  ECONOMIC   ENTOH/OLOGY. 


Fig.   156. 


The  larder-beetle,  Dermes- 
tes  lardariiis. — a,  la'rva  ;  b,  a 
single  hair  from  larva  ;  c,  adult 
beetle. 


These  belong  to  the  family  Dermcstidce,  which  contains  such 
nuisances  as  the  "larder-beetles,"  "carpet-beetles,"  and  "mu- 
seum-beetles." The  elytra,  which  cover 
the  abdomen  completely,  are  black  or 
gray,  usually  ornamented  with  white  or 
colored  scales,  which  sometimes  form 
quite  pretty  markings. 

The     "larder-beetle,"     or     "bacon- 
beetle,"  Dermcstes  lardarms,   is  rather 
more  than  one-fourth  of  an  inch  long, 
and  easily  recognizable  by  having  the 
anterior   half  of  the   wing-covers    pale 
brown  or  yellowish,  its  livery  else  being 
of  a  sombre  black  or  dark  gray.     The 
larva  is  nearly  half  an  inch  in  length, 
rather  narrow  yet  plump,  and  clothed 
with    rather  dense,  long,   brown    hairs. 
It    feeds    on    stored    provisions    of   all 
kinds,  on  hides,  skins,  or  other  similar  substances,  and  is  occa- 
sionally quite  troublesome  in  smoke-houses.     Cleanliness,  plenty 
of  air,  tight  receptacles,  and  close-meshed  wire  netting  on  the 

covers    or   doors   of 
Fig.  157.  pantries    and    boxes 

are  the  best  prevent 
ives,  supplemented 
by  destruction  of  the 
beetles  and  larvae 
where^'er  noticed. 
Good  results  are 
often  obtained  by 
leaving  a  tempting 
bit  in  an  exposed 
position,  which  will 
act  as  a  trap,  attract- 
ing beetles  and  larvae 
where  they  can  be 
easily  found  and  destroyed.  Several  other  species,  similar  in 
size  but  differently  marked,  have  similar  habits,  and  among 
them  the   "leather-beetle,"   D.  znilpiiius,   has  been  responsible 


Leather-beetle,  Dei'mestrs  Tul/>injis. — (7,  Iar\  a  ;  //,  pupa  ; 
k,  adult ;  (/  to  /,  details  of  larva. 


THE    INSECT    WORLD. 


179 


for  much  mischief  in  tanneries  and  factories  producing  leather 
goods.  Where  fumigation  is  possible,  bisulphide  of  carbon  may 
be  employed  with  good  effect,  while  gasoline  readily  destroys 
both  beetles  and  larvae  where  it  can  be  brought  into  contact  with 
them. 

Larvae  similar  to  those  above  described,  but  much  smaller,  are 
often  found  in  museum  collections  on  mounted  animals,  eating 
the  skins,  hair,  and  feathers,  and  in  entomological  collections, 
destroying  the  specimens  entirely.  The  beetles  from  these 
larvae  are  smaller  and  more  ovate,  and  belong  to  the  genera 
Trogodcnna  or  Megatoma.     They  are  often  found  on  flowers 

Fig.  158. 


The  carpet-beetle,  AnUwenus  scrophtilaria . — a,  larva;   b,  larval   skin  split   to  expose 
the  pupa  within  it ;  c,  pupa;  d,  beetle. 


in  this  stage,  in  company  with  species  of  Anthrcnus,  in  which 
the  larvae  are  stouter,  more  clumsy,  equally  clothed  with  hairs, 
but  with  the  ability  to  expand  two  larger  tufts  posteriorly. 
Ajithrenus  also  contains  museum  pests  as  well  as  the  "carpet- 
beetle,"  A.  scropliularia,  which  feeds  on  woollens  in  the  larval 
condition,  and  is  then  better  known  as  the  "  buffalo-moth,"  from 
its  tufted  appearance.  The  beetles  are  very  broadly  oval,  with 
brick-red  scales  along  the  middle  of  the  wing-covers,  and  two 
irregular  white  scaly  bands  transversely  across  the  elytra.  I  have 
found  them  very  early  in  sj)ring  under  the  loose  bark  of  trees 
where  they  had  passed  the  winter.  Later  they  fly  into  open 
windows,  and  lay  their  eggs   wherever  they  And  a  supply  of 


l8o  AN   ECONOMIC  ENTOMOLOGY. 

woollens.  For  this  household  pest  a  liberal  use  of  napthaline  in 
crystals  or  balls,  in  trunks  and  closets,  is  advisable  as  a  pre- 
ventive. Where  woollen  garments  are  to  be  stored  through 
the  summer  they  should  be  first  thoroughly  beaten  or  brushed 
and  sunned  out,  then  wrapped  in  stout  paper  with  the  edges 
pasted,  or  in  cotton  sheeting  well  sewed.  Then,  if  laid  away 
in  boxes  or  trunks,  or  hung  in  closets  with  napthaline  crystals 
between  the  layers,  or  on  the  shelves,  or  among  the  bundles, 
little  danger  is  to  be  feared.  Where  carpets  are  infested,  it  is 
best  to  have  them  taken  up,  thoroughly  beaten  and  cleaned,  and 
the  floors  thoroughly  cleansed  before  they  are  relaid.  Where 
this  is  undesirable  for  any  reason,  gasoline  may  be  used  with 
satisfactory  results.  Except  on  the  cheapest  fabrics  it  may  be 
safely  used  in  liberal  quantities  without  danger  of  injuring  either 
texture  or  colors,  and  wherever  the  liquid  comes  into  contact 
with  either  beetle  or  larva  it  kills  at  once.  Eggs,  however,  are 
not  destroyed,  and  close  watch  must  be  kept  for  a  week  at  least, 
when  a  second  application  may  be  found  necessary  to  reach  the 
larvae  hatched  since  the  first  was  made.  Another  method, 
almost  equally  good  but  more  troublesome,  is  to  place  a  wet 
cloth  over  the  infested  patches  and  press  over  it  with  a  very  hot 
flat-iron,  the  object  being  to  drive  hot  steam  or  vapor  through 
the  fabric  and  thus,  practically,  to  cook  the  insects.  In  collec- 
tions, tight  boxes  or  cases  and  a  free  use  of  napthaline  or 
bisulphide  of  carbon,  or  both,  are  essential. 

Unity  of  habit  in  this  family  is  marred  by  Byturus  zinicolor, 
a  little  yellowish  species  which  is  densely  covered  with  short  silky 
hair,  and  feeds  in  the  blossoms  of  the  red  rasp- 
FiG.  159.  berry,  where  also  its  eggs  are  laid.  The  larvae 
are  white,  nearly  naked,  and  are  found  on  the 
inside  of  the  berry  when  picked.  The  species  has 
not  become  seriously  troublesome  as  yet,  and  is 
mentioned  here  chiefly  because  of  its  unique 
habits. 

Bvluriis  ttnicolor,  rj-.]  tt-  1       •  j  11  1         1   •     • 

'   ^j^j^^    ^  Ine  Jriistertace   are   small,    oval,   slimmg,   very 

hard,  black,  bronzed  or  greenish  beetles,  with  the 

wing-covers  cut  oft'  squarely  behind,  leaving  the  last  segments 

of  the  abdomen  exposed.     The  legs  are  broad  and  flat,  fitted  for 

digging,  and  the  head  is  small,  yet  with  quite  prominent  sharp 


'J UK    INSECT    WORLD. 


I8l 


mandibles  and  capitate  antennae.  They  are  mostly  scavengers, 
the  larvcTp  white  and  somewhat  maggot-like,  occurring  on,  in,  or 
under  all  sorts  oi  excrcmcntitious  or  decaying  animal  or  vegetable 


I'IG.     l6(> 


Fig.  162. 


Hister  atcuatus  ami  Hister  bimacjilatus ,  much  enlarged. 

matter,  in  over-ripe  fungi  or  fruit,  or  under  the  loose  bark   of 
trees.     They  are  of  no  practical  importance  to  the  agriculturist. 

The  Nitidu/idce,  or  "  sap-beetles,"  are  also  small,  more  or  less 
flattened,  always  with  the  tip  of  the  abdomen  exposed  beyond  the 
wing-covers,  and  with  the 
legs  not  specialized  for 
digging  purposes.  They 
feed  in  all  stages  on  de- 
caying or  fermenting  sap 
or  fruits  or  in  fungi,  and 
some  of  them  are  found 
also  on  carrion.  As  a 
whole,  while  the  species 
are  quite  numerously  rep- 
resented and  often  seen, 
yet  they  are  not  either  markedly  beneficial  or  injurious. 

Somewhat  similar  habits  are  met  with  in  the  Trogositidcs, 
which  are  also  flattened  creatures,  most  of  them  living  under 
bark.  Some  of  the  species  of  Tenebrioides,  however, — black 
beetles  about  one-fourth  of  an  inch  in  length,  with  square  thorax 
and  large  head,  known  as  "  cadelles" — are  found  in  .stables, 
barns,  and  mills,  feeding  on  grain,  meal,  and  flour.     They  are 


Carpophilus  hemipterus, 
enlarafed. 


Ips  fasciatus  and  its 
larva,  enlarged. 


l82 


AA   ECONOMIC    ENTOMOLOGY. 


rarely  very   numerous,   and    may  be  kept   in   check  as  recom- 
mended on  a  previous  page  for  the  Ctuujida:. 

There  are  other  small  families  in  the  clavicorn  series,  some  of 
them  interesting  enough  to  the  entomologist,   but  none  of  im- 
portance economically 


Fig.   163. 


Tenebrioides    corticalis,   the    "cadelle." — a,  larva;    b, 
adult ;  c  to/,  structural  details. 


or  likely  to  attract  the 
attention  of  the   cas- 

n\    'C\^   Wm\    \J^^^^|L^/     sl-^^^^^A^^     "^^    observer;    hence 
C-J""Xl 'i^^'-    l.^^'^J  T     ,V\   r       J       hardly  subjects  for  de- 
scription here. 

The  Serricornia,  or 
"saw-horned"  series, 
begins  with  the  family 
DascyllidcE,  contain- 
ing mostly  small  forms 
found  on  dead  or  dy- 
ing trees  or  branches, 
in  which  the  larvae  probably  live.  None  are  of  economic  im- 
portance, a  fact  which  is  also  true  of  the  next  family,  Rhipiceridce. 
This  latter,  indeed,  contains  only  five  species,  all  accounted 
rarities  in  collections,  and  believed  to  breed  in  cedars. 

The  family  -£■/«/<?  nV/.^,  "  spring- beetles,"  "click-beetles,"  or 
"  snapping-beetles, "  contains  numerous  troublesome  forms,  and 
is  easily  distinguishable  in  all  its  stages.  The  beetles  have  the 
prothorax  very  loosely  jointed  to  the  rest  of  the  body,  and  on 

the  under  side   a  curved 
^^"  ^  ^'  process  fits  into  a  cavity 

of  the  meso-thorax. 
When  a  specimen  is 
placed  on  its  back  it 
bends  the  extremities  so 
as  to  raise  the  middle  of 
the  body  from  the  surface,  and  to  bring  the  tip  of  the  curved 
process  to  the  edge  of  the  cavity.  A  sudden  release  of  muscular 
tension  reverses  matters,  sends  the  insect  into  the  air  a  few  inches, 
and  this  "snapping"  or  jumping  performance  is  repeated  until 
it  alights  on  its  feet.  In  the  larval  stage  the  term  "  wire-worms" 
expresses  the  appearance  and  texture  of  the  creature,  and  brings 
to  mind  at  once  an  agent  of  destruction  hardly  surpassed  in  the 


An  Elater  from  side,  to  show  t lie  proslernal  process. 


THE    LXSECT    WORLD. 


^83 


insect  world.  Scarcely  a  farmer  can  be  found  who  has  not  been 
troubled  to  some  extent  by  "wire-worms,"  and  many  a  remedy 
recommended  as  infallible  has  been  tried  and  found  wanting  in 
actual  practice.     We  have  two  series  of  species,  one  of  which 


Fk;.   165. 


Fk;.   166. 


\'\c..  167. 


Fig.  105,  tlie  eyed  Elater,  Alatts  ocitlatus.    Fig.  160,  wood-boring  wire-worm,  from  side- 
Fig.  167,  a,  larva;  b,  adult  click-beetle. 

feeds  in  decaying  wood,  the  other  underground  on  the  roots  of 
plants  ;  of  these  the  first  may  be  left  out  of  consideration  alto- 
gether, though  in  it  may  be  found  the  species  of  Alans,  our 
largest  and  most  prominent  forms.  The  history  of  the  subterra- 
nean species  is  in  general  as  follows  :  The  beetles  appear  quite 
early  in  spring,  and  may  be  noticed  in  fields  where  a  sod  has 
been  turned  down,  during  the  first  days  of  May,  or  earlier  in  the 
Southern  States.  They  fly  quite  rapidly  in  mid-day,  copulate, 
and  later  seek  a  place  to  oviposit.  During  May  or  June,  earlier 
or  later,  according  to  the  species,  the  eggs  are  laid  in  grass-land 
or  where  there  are  plenty  of  weeds, — in  other  words,  wherever 
vegetation,  especially  of  a  grassy  character,  is  abundant.  The 
larvae  hatch  by  midsummer  and  feed  upon  roots,  growing  but 
slowly  and  requiring,  indeed,  in  many  cases,  two  or  three  years 
to  complete  their  development.  Pupation  takes  place  in  fall,  and 
usually  the  change  to  the  adult  also  takes  place  before  winter  sets 
in,  though  they  remain  quiet,  and  do  not  voluntarily  emerge 
until  the  spring  following. 

This  brief  sketch  does  not  apply  in  its  entirety  to  all  the  sub- 
terranean forms  even,  but  it  applies  very  well  to  the  majority 


1 84  AN  ECONOMIC  ENTOMOLOGY. 

of  the  injurious  species.  The  noteworthy  points  are  the  early 
appearance  and  oviposition  of  the  beetles,  the  two-  or  three-year 
life  of  the  larva,  and  the  pupation  and  change  to  adult  in  fall  ; 
all  of  which  must  be  considered  in  the  methods  of  treatment  to 
be  adopted. 
—  The  direct  application  of  insecticides  is  usually  impracticable, 
and  the  texture  of  the  larva  is  so  dense  that  most  contact  poisons 
are  of  little  or  no  avail,  salt  in  large  quantity  having  proved  the 
most  effective.  Stomach  poisons  are  not  easily  applied,  but  on 
an  experimental  scale  it  has  been  found  that  sweetened  dough 
placed  beneath  the  surface  attracts  them,  and  this  can  be  poi- 
soned and  used  as  a  trap.  Practically,  methods  of  cultivation 
calculated  to  avoid  injury  are  most  satisfactory.  Grass  land 
known  to  be  infested  should  be  plowed  in  fall,  and  while  this  will 
not  destroy  any  large  proportion  of  the  larvae,  it  will  kill  most  of 
the  pupae  and  beetles  then  in  the  ground,  so  if  the  practice  be 
continued  for  a  series  of  years  the  insects  will  be  gradually  run 
out.  Wherever  feasible,  crimson  clover  should  be  used  as  a 
sod  crop,  as  this  is  sown  in  late  summer  after  the  beetles  have 
oviposited  and  may  be  harvested  and  plowed  under  shortly  after 
the  beetles  have  laid  eggs,  practically  preventing  the  develop- 
ment of  the  larvae,  especially  if  a  crop  little  or  not  at  all  subject 
to  wire-worms  follows  the  clover.  In  fact,  frequent  change  of 
crops  is  a  most  satisfactory  measure  if  the  land  be  not  allowed  to 
remain  in  grass  more  than  one  year,  and  if  corn  or  potatoes  do 
not  directly  follow  the  sod.  In  light  soil  the  salty  fertilizers  ex- 
ercise a  very  beneficial  effect  when  properly  applied,  and  some- 
times an  advantage  may  be  gained  by  keeping  the  land  in  sod  as 
llong  as  possible,  where  grass  is  needed  as  a  crop.  When  it  has 
"  run  out,"  plow  in  fall  ;  in  spring,  after  cultivating  and  prepar- 
ing for  the  new  crop,  fertilize  heavily,  using  kainit  for  potash  and 
nitrate  of  soda,  so  far  as  possible,  for  nitrogen.  At  least  one 
thousand  pounds  of  kainit  per  acre  should  be  used,  and  this 
seems  exceedingly  disagreeable  to  the  insects  at  all  ages,  and 
fatal  to  the  younger  forms.  Conditions  vary  so  much  in  different 
parts  of  the  country,  and  rotations  are  so  diverse  in  character, 
that  it  is  impossible  to  suggest  any  course  that  will  be  universally 
applicable,  except  the  fall  plowing.  The  suggestions  above  made 
should  be  sufficient,  however,  to  guide  the  intelligent  farmer  in 


THE    INSECT    WORLD. 


185 


Fig.    16S. 


adopting  the  practice  best  suited  to  secure  exemption  in  his  case. 
It  may  be  added,  however,  that  the  fertiHzers  will  not  prove  satis- 
factory unless  applied  as  directed, — i.e.,  in  one  heavy  application 
and  when  the  ground  is  bare. 

The  species  of  the  family  lUipreslidcc  resemble  the  click- 
beetles  in  general  form,  but  theprothorax  is  firmly  articulated  to 
the  rest  of  the  body,  so  that  the  insects  have  no  "springing" 
powers,  and  the  colors  are  metallic.  The  beetles  vary  much  in 
appearance,  but  the  lar\'ie  resemble  each  other  closely,  being 
always  flattened  in  form,  with  greatly  enlarged  anterior  segments. 
They  are  usually  known  as  "  flat-headed  borers,"  sometimes  as 
"  hammer-heads,"  and  infest  not  only  trees  but  shrubs,  vines,  and 
sometimes  even  herbaceous  plants.  Some  of  the  species  prefer 
dead  or  dying  wood,  some  attack  healthy  plants 
only,  while  others,  and  perhaps  the  majority,  are 
somewhat  indifferent,  yet  are  oftener  found  in 
weak  than  in  healthy  and  vigorous  trees. 

Our  largest  Eastern  species  belong  to  the 
genus  Chalcophora,  the  larvae  mostly  feeding  on 
conifers,  though  two  of  them  feed  on  deciduous 
trees  like  the  sycamore.  The  beetles  have  the 
elytra  quite  deeply  and  irregularly  furrowed,  while 
the  colors  are  bronze,  brown,  or  blackish.  I  have 
found  the  larvae  in  quite  old  and  decaying  logs,  but  they  are  said 
to  attack  healthy  trees  as  well,  and  to  cause  occasional  injury. 

The  genus  Dicerca  contains  robust  species,  sometimes  nar- 
rowing so  strongly  toward  the  tip  as  to  seem  almost  tailed 
wing-covers  are  decidedly  convex,  irregularly  corru- 
gated, or  even  reticulated,  with  elevated  spots,  and 
the  colors  are  bright  bronze-brown,  often  with  green- 
ish or  brassy  reflections.  They  are  rarely  common, 
but  infest  a  variety  of  trees,  among  them  peach, 
plum,  apricot,  cherry,  hickory,  oak,  and  pine. 

The  genus  Biiprestis  contains  flattened  species 
with  even  striae  or  ridges,  and  they  are  often  of  a 
brilliant  blue,  green,  or  golden  metallic  color,  occa- 
sionally spotted  and  banded  with  yellow  or  brown. 
The  larvae  feed  mostly  in  conifers,  but  some  also  infest  deciduous 
trees,  none  thus  far  in  dangerous  numbers.      In  Melanophila  the 


Chalcophora      vir- 
giniensis. 


The 


Diccica    di- 
vai  icatiX. 


1 86 


AN   ECONOMIC   ENTOMOLOGY. 


Fig.   170. 


The  flat-head  apple-borer 
Chrysobothris  femorata.  —  a 
larva;  ^,  pupa  ;  rf,  adult. 


wing- covers  are  nearly  smooth  or  with  fine  punctulations  only, 
and  the  larvae  also  feed  principally  in  conifers. 

In  the  genus  Chrysobothris  we  have  forms  that  are  quite  flat- 
tened above,  the  wing-covers  with  irregular  depressions  and 
elevations,  the  prothorax  with  curved 
sides  and  narrower  behind.  Here  be- 
long most  of  the  troublesome  species, 
including  C.  femorata,  the  ' '  flat-headed 
apple-borer,"  which,  despite  its  com- 
mon name,  attacks  a  great  variety  of 
trees.  The  larva  makes  irregular  chan- 
nels and  chambers  in  the  sap-wood, 
boring  into  the  solid  tissues  a  short  dis- 
tance only,  just  before  pupation,  and 
this  describes  also  the  habits  of  many 
of  the  other  species  of  this  genus.  The 
eggs  are  laid  on  the  bark  in  June  or 
July,  and  the  larvae  hve  from  one  to 
three  years  before  coming  to  maturity. 
Pupation  occurs  shortly  before  the  pe- 
riod at  which  the  adults  emerge. 

The  genus  Agriliis  contains  species  differing  from  any  of  those 
heretofore  mentioned  by  their  slender,  cylindrical  form,  the  head 
squarely  truncate,  or  cut  off"  in  front,  the  elytra  much  narrowed 
at  tip.  As  a  rule,  the  species  are  dull 
brownish-bronze  in  color,  the  prothorax 
sometimes  brassy  or  red-bronzed,  and 
none  is  better  known  than  the  ' '  red- 
necked blackberry-borer,"  Agrilus  rufi- 
collis,  the  author  of  the  "gouty  gall"  on 
that  plant.  The  larvae  in  this  genus  are 
unusually  long  and  flattened,  the  seg- 
ments strongly  marked,  the  ' '  head' '  not 
much  wider  than  the  body,  and  the  anal 
foi^ks  distinct,  differing  in  each  species. 
Returning  to  the  blackberry-borer,  it  is 
good  practice  to  cut  out  all  galled  canes  early  in  spring  and  burn 
them.  Trimming  is  done  at  this  time  as  a  matter  of  regular 
cultivation,  and  the  galls  are  then   easily  seen.      No   "galled" 


Fig.  171. 


Blackberry  -  cane 
Agrilus  ruficollis. — b 
c,  adult. 


borer, 
larva  ; 


THE    INSECT    WORLD. 


187 


cane  ever  ripens  a  fair  set  of  berries,  and  it  might  as  well  be  cut 
out  at  once.  Another  satisfactory  method  is  to  cut  off  all  the 
new  shoots  at  the  surface  of  the  ground  about  the  end  of  June. 
At  this  time  all  the  beetles  have  laid  their  eggs,  and  the  shoots 
which  come  up  in  July  cannot  become  infested.  The  best  results 
will  be  obtained  by  combining  both  methods.     Cutting  the  new 

Fig.  172. 


-XZ. 


Blackberry-gall  maker.— a,  gall  just  beginning  to  form  over  recent  borings  ;  *,  section 
through  an  old  stem  to  show  the  character  of  the  gall. 


shoots  causes  the  death  of  the  young  larvae,  which  are  unable  to 
subsist  on  dead  wood,  and  being  footless  are  unable  to  migrate 
to  new  stalks. 

Another  species  of  Agrihcs  seriously  injurious  in  parts  of  the 
Eastern  United  States  is  the  "sinuate  pear-borer,"  A.  sinuatus, 
imported  from  Europe  within  recent  years.  This  feeds  between 
bark  and  wood  in  pear-trees,  making  immensely  long  zig-zag 
galleries,  finally  girdling  the  tree  and  killing  it.  It  lives  two 
years  in  the  larval  stage. 

In  general  we  are  very  helpless  against  boring  larvae  once  they 
get  into  the  trunk  of  a  tree.  Cutting  out  is  a  tedious  process, 
even  if  the  location  of  the  larva  is  easily  discoverable,  which  it 
often  is  not.     We  must,  therefore,  try  to  prevent  their  entrance, 


1 88  ^^V   ECONOMIC   ENTOMOLOGY. 

and  this  may  be  done  more  or  less  completely  by  mechanical 
means.  As  against  the  larger  species — i.e.,  against  all  except 
Agrilus — a  wire  mosquito  netting  loosely  encircling  the  trunk,  so 
as  not  to  touch  it  anywhere,  is  a  complete  protection.  The  in- 
sects lay  their  eggs  under  a  bark  scale,  or  on  smooth  bark  gnaw 
a  little  hole  in  which  the  ^^^  is  laid,  and  if  access  to  the  bark  be 
prevented  they  seek  other  localities.     The  wire  must  be  tied  at 


Fig.  173. 


The  sinuate  pear-borer,  Agrilus  sitiuatus. — a,  beetle  ;  b,  larva  ;  c,  its  anal  fork  ;  d, 
pupal  chamber  with  pupa  in  position. 

the  top  to  prevent  beetles  getting  under  it,  and  must  extend 
underground  an  inch  or  so.  In  this  way  we  not  only  prevent 
new  infestation,  but  any  beetles  that  may  emerge  from  the  trunk 
will  be  hopelessly  imprisoned  and  will  die  without  a  chance  to 
reproduce. 

Instead  of  wire  netting,  tarred  paper  or  even  newspapers 
tightly  wrapped  around  the  trunk  to  the  branches  will  answer 
an  excellent  purpose,  needing  renewal  each  year,  however,  where 
the  wire  netting  lasts  several  seasons.     Thorough  whitewashing 


THE    INSECT    WOKf.n.  189 

offers  a  large  measure  of  protection,  since  the  adults  will  not  vol- 
untarily eat   through  a  coat  of  it,  and  the  larvae  cannot  do  so 

Fig.  174. 


Work  of  tlif  sinuate  pear-lxini-  011  a  Uartlett  pear-tree  :  about  one-fourth  natural  size. 

when  first  they  emerge  from  the  ^%'g.     The  whitewash  can  be 


igo 


AX   ECONOMIC  ENTOMOLOGY. 


applied  with  a  knapsack  pump  through  a  Vermorel  nozzle,  and 
a  little  Paris  green  adds  greatly  to  its  effectiveness.  It  should 
be  renewed  every  week  or  two  until  the  middle  of  July,  when  the 
danger  from  these  flat-headed  borers  may  be  considered  at  an 
end,  and  it  has  the  advantage  of  protecting  the  branches  as  well 
as  the  trunk.  The  admixture  of  a  little  glue  or  salt  will  improve 
its  adhesive  and  lasting  qualities. 

A  strong  fish-oil  soap,  say  one  pound  in  one  gallon  of  water, 
is  also  effective  and  may  be  applied  in  the  same  manner.  It 
forms  a  film  of  soap  over  the  bark,  and  is  repellent  to  the  beetles 
as  well  as  fatal  to  the  young  larvae.  The  admixture  of  an  ounce 
of  crude  carbolic  acid  to  a  gallon  of  suds  is  advantageous.  This 
mixture  should  not  be  applied  to  leaves  or  on  young  shoots, 
as  it  would  probably  cause  injury.  As  these  methods  are  all 
preventive  rather  than  remedial,  they  must  be  promptly  and 
thoroughly  applied,  and  success  will  be  in  proportion  to  the 
thoroughness  with  which  the  work  is  done.  Instead  of  any  of 
the  preceding  methods,  "insect  lime"  or  "  dendrolene "  may 
be  with  proper  precautions  employed  on  the  trunks  and  larger 
branches,  and,  practically,  this  is  the  best  material  for  use  against 
the  "sinuate  pear-borer."  It  can  be  easily  applied,  remains 
effective  for  weeks,  and  one  application,  properly  made  at  the 
right  time,  will  protect  the  trees  for  the  season.  As  against  the 
pear-borer,   it  should  be  applied  not  later  than  May  15th,  and 

kept  intact  until  June 
Fig.  175.  15th,  when  all  danger 

from  that  pest  is  over. 
Reference  should  be 
made  to  the  chapters 
on  insecticides  and 
preventives  for  further 
details  as  to  applica- 
tions. 

In  the  next  series, 
the  Lainpyridce,  there 
are  no  species  injurious  to  vegetation,  though,  under  the  name 
"fire-flies,"  some  of  them  are  well  known.  The  beetles  are 
usually  slender,  somewhat  flattened  above,  with  a  more  or  less 
retracted  head,  and  are  of  a  soft  leathery  texture.     The  ' '  fire- 


Fire-fly,  Photinus  pyralis. — cr,  larva;    *,  pupa  in  cell 
c,  adult ;  diof,  structural  details  of  larva. 


THE    INSECT   IVORf.D. 


191 


Fig.  176. 


flies  "  are  first  noticed  in  June  in  the  more  northern  and  central 
portions  of  tlie  United  States,  and  have  the  terminal  segments 
of  the  abdomen  on  the  under  side  of  a  bright  sulphur-yellow 
color,  which  at  the  will  of  tlie  insect  glows  with  a  phosphorescent 
light  of  considerable  illuminating  power.  They  hide  during  the 
day  on  the  foliage  of  plants  or  in  crevices,  and  begin  their  flight 
with  the  deepening  of  the  twilight.  In  some  species  the  female 
is  without  wings  and  remains  on  the  ground  among  the  grass — 
the  "glow-worm."  The  larva-  are  predaccous,  and  some  of 
them  live  on  snails. 

Belonging  to  the  same  family,  but  of  a  diurnal  habit  and  with- 
out the  illuminating  power,  are  the  "soldier-beetles,"  belonging 
to  the  genera  Chaiiliogna- 
thus  and  Tclcphonis,  dis- 
tinguished also  by  having 
a  more  prominent  head 
and  large,  round  eyes. 
These  may  be  found  on 
flowers,  where  they  prob- 
ably feed  on  pollen,  but 
are  of  direct  benefit  by 
aiding  in  pollination.  The 
larvae  are  even  more  de- 
cidedly useful,  being  predaceous  and  feeding  largely  on  soft- 
bodied  grubs  and  the  like.  They  are  long  and  slender,  flattened 
above  and  somewhat  narrowed  at  each  end,  or  fusiform,  the 
edges  of  the  segments  quite  prominently  marked.  They  are 
especially  effective  against  such  creatures  as  the  larvae  of  the  plum 
curculio  when  they  enter  the  ground  to  pupate,  and  a  large  pro- 
portion are  thus  disposed  of  annual!}-. 

The  species  belonging  to  the  family  Malachiid(£  resemble  the 
Lampyrids  in  the  soft  body  texture  and  leathery  wing-covers, 
but  they  are  much  shorter  and  broader,  the  broadest  part  of  the 
body  coming  near  the  end  of  the  wing-covers.  The  antennae 
are  short,  a  little  enlarged  at  the  tip,  and  often  curiously 
knotted  in  the  male.  Many  of  the  species  have  soft,  orange- 
colored  vesicles,  capable  of  being  protruded  from  the  side  of 
the  body.  They  are  usually  found  on  flowers  and  feed  on  other 
insects  or  insect  eggs,  probably  doing  much  good  in  this  way. 


Soldier-beetle,  Cliaitliogtuitlius  pennsylvanicus. 
— a,  larva;  b,  its  head  enlarged;  c  to  A,  struc- 
tural details;  /,  beetle,  natural  size. 


19: 


A.V   ECONOMIC  ENTOMOLOGY. 


The  larvae  of  only  a  few  species  are  known,  and  these  are  pre- 
daceous. 

Next  come  the  CleridcB,  many  of  which  are  also  flower-beetles, 
but  with  longer  legs,  more  prominently  enlarged  antennae,  more 

slender  cylindrical  form,  and  much 
Fig.  177.  firmer   texture.      They  are   bright 

colored,  as  a  rule,  often  prettily 
banded,  and  sometimes  quite  abun- 
dant.    Many  species  are  found  on 

Fig.  178. 


Malachius  marginicollis  :   much 
enlarged. 


Clef  us  apivorus. — a,  larva  ;   b,  pupa  ; 
beetle  central :  all  enlarged. 


the  trunks  of  trees,  running  about  rapidly  and  somewhat  resem- 
bling ants.  Their  larvae  in  such  cases  prey  upon  wood-boring 
insects,  principally  such  as  live  in  sap-wood,  and  they  are  slender, 

with    short    legs    and    a 
Fig.  179.  prominent,        somewhat 

pointed  head.  They  are 
extremely  useful  in  keep- 
ing in  check  bark-beetles 
and  other  borers,  and  are 
thus  worthy  of  our  dis- 
tinguished consideration. 
Most  of  the  other  species 
are  also  predaceous  in 
the  larval  stage,  but 
hardly  beneficial,  since  they  live  in  the  nests  of  bees,  devouring 
both  the  larvae  and  the  food  stored  for  them.      Clenis  apivorus 


Red-legged  ham-beetle,  Coryuetcs  rufipes.—  a, 
larva;  6,  pupa ;  c,  cocoon  ;  d,  e,  beetle,  enlarged 
and  natural  size  ;  /toj,  structural  details. 


THE    IXSKCT    WORLD. 


193 


infests  the  hives  of  the  common  honey-bee,  and  is  more  or  less 
of  a  nuisance  in  some  locahties. 

The  ahiiost  inevitable  exception  occurs  in  this  family  also,  and 
the  species  of  Coryuetes,  blue  or  part  blue  and  part  orange  in 
color,  live  upon  dead  or  dry  animal  matter,  often  attacking  pro- 
visions. The  "red-legged  ham-beetle,"  C.  7'iifipes,  is  of  this 
type,  and  will  serve  to  illustrate  the  series.  The  measures  recom- 
mended as  against  the  Dcrmcstidce  will  answer  here  as  well. 

In  the  family  PtinidcE  we  have  an  aggregation  of  oddities  diffi- 
cult of  general  definition,  save  that  as  a  rule  the  species  are 
small,  with  retracted  head,  more  or  less  cylindrical  firm  body,  and 
firm  wing-covers.  They  feed  in  the  larval  as  well  as  adult  con- 
dition on  dry  animal  or  vegetable  matter,  though  some  species 
attack  green  vegetation.  Many  live  in  dead  branches  or  twigs, 
and  only  a  few  are  of  sufficient  interest  to  be  especially  noted. 
Of  these  is  the  "death-watch,"  Sitodrepa  panicca,  so  named 
from  the  ticking  sound  frequently  made  by  the  beetle  when 
working  in  wood,  which  superstition  has  interpreted  as  a  warning 
of  approaching  death.  It  works  also  in  a  great  variety  of  other 
substances,  ranging  from  gunwads  to  roots  of  hellebore  and  old 
books,  as  a  fleshy,  white,  grub-like  larva,  with  a  brown  head  and 
a  surface  covered  with  short,  brown,  bristle-like  hairs.  Where 
the  nature  of  the  article  admits  of  such  treatment,  exposure  to 
the  fumes  of  bisulphide  of  carbon  is  a  good  remedy,  as  is  also 
saturating  with  gasoline  or  benzine.  A  liberal  use  of  paint  with 
plenty  of  turpentine  is  indicated  in  other  cases,  and  sometimes 
mere  cleanliness  following  the  destruction  of  hopelessly  infested 
material  will  answer  every  purpose. 

Of  the  same  general  shape,  but  larger  and  broader,  with  smooth 
instead  of  striated  wing-covers  and  a  "humped"  form,  is  the 
Lasioderma  serricorne,  popularly  known  as  the  "tobacco-"  or 
"  cigarette-beetle."  It  is  a  great  lover  of  tobacco  in  all  its  forms, 
the  lar\'a  relishing  plug,  long  or  fine  cut,  chewing  or  smoking,  in 
cigarette,  cigar,  or  leaf,  almost  equally  well,  and  injuring  it 
materially  for  the  human  user  of  the  "  weed."  The  matter  is  an 
important  one  to  manufacturers,  who  deal  with  it  in  a  variety  of 
ways  ;  but  it  does  not  particularly  interest  the  farmer. 

Among  the  wood-feeders  the  species  of  Bostrychiis  and  Si7i- 
oxylon  are  of  interest,  their  larvae  sometimes  boring  into  fruit-trees. 

13 


Fig.  I  So. 


Fig.  180,  cigars    injured  by  the   tohacco-beolle,  Lasioderma  seryicorne ;   holes  show 
where   the   beetles   issued.      Fig.    181,   Lasioderma   serricorne,   from   above   and   side. 
Fig.  182,  the  "  death-watch,"  Sitodrcpa  panicea,  larva  and  beetle,  from  above  and  side; 
much  enlarged. 
194 


THE    JXSECr    WORLD. 


195 


The  "  apple-twig  borer,"  Amphicerus  bicaudatus,  is  about  the 
only  species  needing  especial  remark,  and  this  beetle  bores  into 
small  apple- twigs  in  early  spring,  entering  close  to  a  bud  and 
making  a  channel  several  inches  in  length,  apparently  for  food 
and  shelter  merely.  It  remains  in  these  burrows  a  short  time 
only,  and  then  lays  its  eggs  in  the  dead  or  dying  roots  of  "  cat- 


FiG.   183. 


Apple-twig  borer,  Amphicrrus  bicaudatus.— a,  beetle,  from  above  ;  b,  same,  in  outline,  from 
side  ;  d,  larva  ;  g,  pupa  ;  h,  same  in  larval  burrow  ;  c,  e,/,  structural  details. 

brier,"  or  "  greenbrier"  {Smilax  sp.),  or  in  dead  shoots  of 
grape.  The  insects  rarely  appear  in  troublesome  numbers,  and 
then  good  practice  is  to  look  after  neglected  vineyards  or  grape 
tangles  in  near-by  woods,  and  after  brier  thickets,  which  latter 
are  an  abomination  at  best  and  should  be  destroyed. 

There  are  other  Serricorn  families,  small  both  in  size  and  in 
the  number  of  species  they  contain,  but  they  are  mostly  rare,  of 
no  economic  importance,  and  need  not  be  referred  to  here  even 
by  name. 


196 


AiV  ECONOMIC  ENTOMOLOGY. 


The  next  large  series  is  the  Lamellicomia,  where  the  antennae 
terminate  in  a  lamellate  or  leaf- shaped  club.  All  the  species  are 
feeders  upon  vegetation,  living  or  dead,  green  or  in  a  stage  of 
decay,  and  in  all  cases  the  larvae  are  "white  grubs,"  large  or 
small,  smooth  or  hairy,  but  always  "  white  grubs."  These  can 
be  generally  described  as  having  a  large,  yellow,  or  brown  head, 
with  prominent  mandibles  and  long  palpi,  legs  that  are  quite  long, 
moderately  stout,   with    distinct    claws  at  the  tip,    usually  also 


Fig.  I 


Stag-beetles.— I,  Lucaniis  claphus,  male;    2,  L.  dama,  male. 


clothed  with  hair,  a  body  that  is  cylindrical,  stout,  wrinkled, 
somewhat  curved  or  even  crescent-shaped,  ending  rather  abruptly 
in  a  more  or  less  enlarged,  obtuse,  terminal  bulb.  As  a  rule, 
the  color  is  dirty  yellowish  white,  but  it  may  become  pink, 
greenish,  or  even  blackish,  the  hinder  portion  always  showing 
darker  because  of  the  excrementitious  mass  which  shows  through 
the  transparent  tissue. 

Two  families  belong  to  this  series,  of  which  the  Lucam'd^,  or 
stag-beetles,  are  of  no  economic  importance  though  of  much 


THE    IXSF.CT   WORLD. 


197 


Fig.   1S5. 


popular  interest.  They  differ  from  the  Scarabcrida;  in  that  the 
leaves  of  the  club  are  separated  and  cannot  be  made  to  form 
a  solid  club  or  mass. 

Our  most  common  "  staj^-lK'etle"  is  the  Lucanus  dama,  in 
which  the  mandibles  of  the  male  are  much  enlarged  and  sickle- 
shaped  ;  whence  the  common  term  "  pinching-bug."  It  occurs 
throughout  the  Mitldle  and  Central  States,  becoming  more  rare 
to  the  North  and  losing  interest  in  the  South  in  favor  of  its  more 
prominent  relative,  the  L.  elaphus,  which  in  the  male  has  man- 
dibles almost  as  long  as  itself,  and  branched  like  antlers,  yielding 
in  this  respect,  however,  to  its  European  congener,  the  L.  cervus, 
or  original  "stag-beetle."  Quite  a  different-looking  creature  is 
the  Passaliis  cormdiis,  perhaps  the  most  common  of  all  the 
members  of  this  family,  though  not  always  readily  found.  It  is 
coal-black,  shining,  with  a  large  square  thorax  and  a  small  head 
armed  with  a  short  curved  horn.  All 
these  species  and  all  the  larvae  of  this 
family  feed  in  decaying  wood,  and 
preferably  in  stumps  or  in  roots.  Thus 
their  function  is  rather  as  scavengers, 
and  never  as  destroyers  of  vegetable 
life.  The  larva  of  the  Passaliis  cormitus 
is  interesting,  because  it  has  four  legs 
only,  one  pair  being  entirely  aborted. 

In  the  family  Scarabczidce  the  leaves 
of  the  antennal  club  are  always  close 
together  when  at  rest,  but  can  be  spread 
out  fan-like  at  the  will  of  the  insect, 
exposing  the  numerous  sensory  pittings 
with  which  they  are  closely  set.  The 
legs  are  always  fitted  for  digging. 

At  the  beginning  we  meet  a  series  of  i^'^^'^aih 
species  that  are  scavengers,  living  on 
decaying  or  excrementitious  matter.  Some  of  them  are  large 
and  have  the  curious  habit  of  making  balls  of  dung,  in  each  of 
which  an  ^^'g  is  laid.  The  balls  are  then  buried  beneath  the 
surface,  and  each  furnishes  sufficient  food  to  bring  one  larva  to 
maturity.  When  the  ball  is  made  up  on  a  road  or  other  hard 
surface,  the  insects  roll  it  to  some  more  suitable  place,  and  have 


AN   ECONOMIC   ENTOMOLOGY. 


therefore    received    the    popular    name 


Fig.    i86. 


'  tumble-bugs."  The 
beetles  are  usually 
blackish  or  bronze 
brown  in  color,  but 
sometimes  bril- 
liantly metallic  blue, 
green,  coppery,  or 
bronzed,  and  often 
we  find  in  the  male 
a  prominent,  curved 
horn  on  the  top  of 
the  head,  and  angu- 
lar processes  on  the 
thorax. 

Other  large  or 
moderate-sized  spe- 
cies make  holes 
close  to  or  under 
droppings  in  fields, 
working   mostly  at 


A    "tumble-bug,"    Copris   Carolina.— a,    larva;     b,   the       nio'ht       and    Icavingf 
cell  in  which  it   lived;  c,  pupa;    d,  female  beetle;  e  to  i, 
structural  details. 


evidences    of   their 


Fig.  187. 


presence  in  the 
shape  of  little  piles  of  fresh  dirt  next  to  or  even  on  top  of  the 
droppings ;   cow-dung  being  the  favorite    food.     These  beetles 

usually  have  deeply  striated  wing- 
covers,  are  more  stockily  built 
than  those  previously  mentioned, 
and  belong  mo.stly  to  the  genus 
Geofrypes. 

A  series  of  small,  more  slender 
or  oblong,  black  or  reddish  beetles 
is  often  found  in  considerable  num- 
bers burrowing  in  or  under  excre- 
ment, and  these  have  similar  habits 
and  are  referable  to  the  genera 
ApJiodius  or  Atceniiis. 

Very  often  large,  clumsy  "white 
grubs"    are   found   in   manure   heaps,    and   these   are  larvae  of 


Apliodius  granarius,  much  enlarged. 


THE    IXSECT   WORLD. 


199 


beetles  helonyinq-  to  this  scries.  None  of  them  are  in  any  way 
injurious. 

The  e.xeeption  in  food  habits  in  this  family  i.s  found  in  the 
genus  Trox,  containing  oblong,  very  convex  species,  with  rough, 
tuberculate  or  pitted  wing-covers,  and  a  deeply  furrowed  thorax. 
They  are  usually  more  or  less  incrusted  with  dirt,  are  found 
feeding  under  old  skins,  bones,  or  hoofs,  and  are,  as  scavengers, 
at  least  innoxious. 

The  more  typical  ' '  leaf-chafers' '  are  of  diverse  forms,  often 
common  and  economically  important.     Among  the  first  we  reach 

Fig.  188. 


Rose-chafer,  Macrodaclyliis  suhspinosus. — a,  beetle  ;  b,  head  and  thorax,  in  outline,  from 
side  ;  ^  to  ^,  structural  details. 

the  genus  Macrodactylus,  of  which  the  "rose-chafer,"  or 
"rose-bug"  is  a  member.  This  appears  in  June  at  about  the 
time  roses  and  grapes  come  into  blossom,  and  eats  their  flowers 
in  preference  to  anything  else. 

Occasionally,  for  a  series  of  years,  the  insects  appear  in  ever- 
increasing  abundance,  until  the  swarms  are  so  great  that  they 
ruin  not  only  vineyards  but  orchards  and  gardens,  eating  almost 
every  kind  of  fruit  and  flower.  In  the  presence  of  such  swarms 
we  are  almost  helpless,  and  insecticides  are  of  no  possible  use. 
No  contact  poison  kills  them,  and  the  arsenites  or  other  stomach 


AA^   ECONOMIC   ENTOMOLOGY. 


poisons  act  too  slowly,  as  two  or  three  days  suffice  to  ruin  a  vine- 
yard. Lest  this  seem  strange,  I  will  state  that  I  have  seen  on 
hundreds  of  acres  of  vineyard  every  vine  bearing  multitudes,  and 
every  bunch  of  blossoms  from  two  to  ten,  or  even  more  beetles. 
I  have  counted  over  twenty  on  a  single  apple,  and  a  full-blown 
rose  may  bear  as  many  as  thirty  or  even  more.     We  are  reduced 


Fig 


Larva,  a,  and  pupa.y",  of  rose-chafer  ;  b  Xo  e,  ,i; ,  It,  structural  details. 

to  actually  collecting  the  specimens  from  the  vines  by  means  of 
funnel  or  umbrella- shaped  collectors,  adapted  to  the  method  of 
cultivation  in  use.  They  drop  readily  when  the  vines  are  jarred, 
and  the  collector  should  be  so  made  as  to  roll  them  to  the  centre 
and  into  an  attached  pail  containing  kerosene.  This  must  be 
done  not  only  daily,  but  continuously  for  several  days  until  the 
flight  is  over  or  the  grapes  have  set,  for  well-set  grapes  are 
rarely  eaten.  Fortunately,  a  period  of  abnormal  increase  seems 
to  be  followed  by  a  period  of  decrease,  though  the  lengths  of  the 
periods  have  not  been  ascertained.  The  larvae  feed  in  light  land 
on  the  roots  of  various  plants,  but  principally  on  grass.  They 
pupate  in  spring,  shortly  before  changing  to  the  ?dult  condition, 
and  by  ploughing  infested  sod  at  this  time  a  large  proportion  can 
be  destroyed.  When  only  moderate  numbers  occur,  lime  often 
serves  to  protect  the  plants,  or,  better,  the  Bordeaux  mixture, 
which  is  distasteful  to  them. 

The    "May-beetles,"    or     "June-bugs,"   sometimes     termed 
"  cockchafers,"  are  much  larger,  and  mostly  members  of  the  genus 


THE    INSECT'   irOR/.D. 


Lachnostcrna.  Tliey  fly  at  night,  are  readily  attracted  to  light, 
and  often  come  into  rooms,  clumsily  and  noisily  bumping  against 
all  sorts  of  obstructions  until  they  c\enlually  strike  something 
which  sends  them  heavily  to  the  floor.  We  ha\e  many  species 
more  or  less  resembling  each  other,  and  all  chestnut  brown  or 
yellowish  in  color.  Some  years  they  are  very  abundant  and 
cause  injury  by  eating  the  foliage  of  trees  or  shrubs.  I  have 
found  them  eating  pieces  out  of  the  stalks  of  recently  set  apples 

Fig.  190. 


May-beetle. — i,  pupa  in  earthen  cell  ;  2,  larva  or  white  grub  ;  3,  4,  beetle, 
from  side  and  above. 

and  pears,  causing  the  fruit  to  wilt  and  drop.  The  larvae  live 
on  grass  and  other  roots,  and  are  typical  "  white-grubs."  Culti- 
vated crops  are  frequently  attacked  and  much  injury  is  some- 
times caused.  The  larval  period  has  not  yet  been  satisfactorily 
determined  for  all  species,  and  varies,  as  does  also  the  time  for 
changing  to  the  adult  condition.  Frequent  rotation  and  fall 
ploughing  are  to  be  recommended,  and  where  grass  lands  are 
infested,  heavy  top-dressings  of  kainit  and  nitrate  of  soda  have 
proved  beneficial.  Wherever  ploughing  is  done  in  infested  fields, 
chickens  should  be  encouraged  to  follow  in  the  furrow  to  pick 
up  the  grubs. 

Where  young  trees  are  to  be  protected  from  the  beetles,  jarring 
them  into  an  umbrella  two  or  thrte  times  early  in  the  evening 


202  AN  ECONOMIC  ENTOMOLOGY. 

will  prove  effective,  as  they  do  not  fly  much  after  nine  o'clock, 
except  on  unusually  warm  and  sultry  nights. 

Frequentl)-  we  iind  on  grape  and  Virginia-creeper,  during 
midsummer,  a  small  chafer  witii  clay-yellow,  rather  shining,  and 
striated  wing-covers,  feeding  upon  the  leaves.  This  is  the 
Anomala  lucicola,  which  varies  also  to  a  shining  black.  It  is 
occasionally    nimierous    enough    to    cause    notable    injury,    but 


P'iG.  191. 


Fig.  192. 


Anomala  lucicola.— a,  b,  lar\'a  ;  c,  pupa  in 
larval  skin  ;  d,  r,/,  adult  beetles. 


Goldsmith   beetle, 
Cotalpa  huiigi'ra. 


yields  readily  to  any  of  the  arsenites.  The  larvae  live  in  light 
soil,  feed  upon  the  roots  of  grasses,  and  pupate  in  late  fall,  the 
adult  forming  soon  after  and  remaining  within  the  cast  larval 
skin  until  ready  to  emerge  in  early  summer. 

Also  found  during  the  day  on  grape  foliage,  or  flying  toward 
it  during  early  evening,  is  a  large,  shining,  tan-yellow  chafer, 
with  eight  black  spots,  two  on  the  thorax  and  six  on  the  wing- 
covers.  This  is  the  Pelidnota  punctata,  or  ' '  spotted  vine-chafer, ' ' 
which  feeds  upon  the  leaves,  but  rarely  does  noticeable  injury. 
The  larvae  feed  upon  decaying  roots  and  stumps,  and  I  have 
taken  both  lar\a  and  pupa  out  of  a  rotten  cedar  trunk. 

Swamp-willow  in  the  East  is  the  food  of  Cotalpa  lanigera,  a 
beetle  very  similar  in  size  and  shape  to  the  preceding,  but  of  a 
beautiful  shining,  lemon  yellow,  the  head  glittering  with  a  golden 
sheen,  hence  known  as  the  "goldsmith  beetle."  Beneath  it  is 
of  a  burnished  copper  color,  densely  clothed  with  white  woolly 
hair.  It  is  not  injurious,  and  mentioned  here  only  because  of  its 
beauty.  Some  of  its  allies  in  the  Southwest  and  in  the  tropics 
are  of  the  most  brilliant  golden  and  silvery  tints, 


THE    INSECT   WORLD. 


203 


A  beetle  that  sometimes  does  considerable  injury  to  sugar-cane 
and  corn  in  the  Southern  States  is  the  "  sugar-cane  beetle,"  Li- 
•rynis  rugiccps.  Unfortu- 
nately, we  do  not  yet  know- 
its  entire  life  history,  aiul,  as 
the 'injuries  seem  to  have 
been  rather  local  and  occa- 
sional, it  may  b^  that  it  will 
not  prove  of  wide  or  gen- 
eral importance.  No  satis- 
factory method  of  dealing 
with  it  is  known  at  present. 

In  the  genera  Xyloyctcs, 
Strategus,  Dynastcs,  and 
Philcuriis,  we  have  a  series 
of  species  more  or  less 
bizarre  in  form,  with  curious 
horns  and  processes  on 
head  or  thorax  or  both,  but 
not  of  economic  interest, 
since  neither  beetles  nor 
larvae  are  found  on  culti- 
vated plants.  Ash  furnishes 
food  for  several  of  the  spe- 
cies in  both  larval  and  adult 
form. 

Beginning  with  the  genus 
Allorhina^  we  have  a  series 
of  beetles  that  frequent 
flowers,  feeding  on  pollen, 
but  largely  repaying  what 
they  devour  by  the  benefit 
they  confer  in  poUenizing. 
Sometimes,  however,  they  prefer  ripening  fruits  or  even  corn 
when  in  milk,  and  then  become  troublesome.  Belonging  to  this 
genus  Allorhina  are  velvety-green  and  dull-brown  beetles,  an 
inch  or  more  in  length,  which  fly  during  the  day  with  a  buzzing 
sound  somewhat  like  a  bumble-bee,  and  usually  close  to  the  sur- 
face of  the  ground,  except  where  they  attack  fruit.     Yet  I   have 


W.V\.U\GUO\-S. 


Ligvvus  rugict'ps. — The  beetle  and  its  work. 


204 


AN  ECONOMIC  ENTOMOLOGY. 


seen  hundreds  of  them  flying  about  among  half  a  dozen  pkim- 
trees,  apparently  injuring  nothing  but  possibly  themselves. 
Their  larvae,  however,  feed  on  grass  roots  and  are  often  trouble- 
some on  lawns.  They  are  quite  large  creatures  and  very  hairy, 
with  a  fashion  of  travelling  on  the  back  instead  of  the  legs,  when 
removed  from  their  congenial  soil.  Heavy  top-dressings  of 
kainit  and  tobacco  have  proved  about  as  effective  as  anything  in 
dealing  with  these  insects,  though  on  a  small  scale  the  kerosene 
emulsion  diluted  ten  times,  and  then  washed  into  the  soil  by  rain 
or  frequent  waterings,  has  proved  effective.     On  any  large  area 

Fig.  194. 


Alio)  hina  nitida.—a,  larva  ;  b,  pupa  ;  c,  adult ;  d  io g,  structural  details  of  larva. 


this  process  would  probably  be  too  expensive.  The  species  is 
more  common  southward,  and  is  more  likely  to  become  trouble- 
some on  lawns,  in  parks,  and  in  gardens  than  in  the  field. 

To  this  same  group  belongs  the  "Indian  Ceionia.,'' Euphoria 
inda,  which  is  one  of  the  earliest  of  our  Eastern  beetles,  flying 
in  April  or  May  over  sandy  or  bare  spots,  close  to  the  ground. 
At  this  time  it  is  sometimes  found  on  flowers,  but  remains  only 
a  few  days.  In  early  September  a  new  brood  appears,  and  this 
is  occasionally  troublesome,  the  beetles  eating  into  ripe  fruits  or 
into  corn.  They  have  never  yet  appeared  in  such  numbers, 
however,  as  to  make  remedial  measures  necessary. 

Taken  as  a  whole,  the  Lamellicorns  contain  no  directly  bene- 
ficial insects,  and  the  white-grub  larvae  are  in  many  cases  injurious 
when  they  feed  on  the  roots  of  cultivated  plants.  Where  a 
variety  of  cultivated  crops  follow  each  other,  there  is  little  chance 
for  their  excessive  development,  and  frequent  rotation  is  there- 
fore indicated,  with  as  short  a  period  in  grass  as  may  be.     As 


THE    INSECT   WORLD.  205 

the  beetles  in  most  cases  appear  in  spring  and  oviposit  late  in 
May  or  in  June,  land  bare  at  that  time  will  probably  escape. 
Fall  sowing  of  crimson  clover,  to  be  turned  under  by  the  middle 
ol"  May  or  before,  will  in  some  cases  protect  the  land  and  act  as  a 
green  manure  if  required  ;  or  it  may  be  allowed  to  remain  until 
mature  to  make  hay,  and,  if  then  ploughed  and  put  into  potatoes 
or  some  crop  which  tlie  white-grubs  do  not  attack,  such  as  are 
then  in  the  ground  will  be  starved  out.  Where  white-grubs  are 
abundant,  strawberries  should  not  follow  sod  or  other  grass  crop 
directly,  and  the  beds  should  be  kept  clean,  at  least  through  the 
second  year.  Where  the  culprits  are  species  of  Lac/mosterna, 
fall  ploughing  is  indicated,  since  this  will  turn  out  the  newly-formed 
beetles  at  an  unseasonable  period,  and  will  cause  their  death  in 
most  cases. 

We  now  reach  the  great  series  of  P/iytophaga,  in  which  the 
tarsi  are  apparently  four-jointed,  the  third  joint  deeply  lobed. 
Two  families  belong  here, — the  Cerambycidcs,  or  long-horned 
beetles,  and  the  Chrysomclidce,  or  leaf-beetles.  The  ' '  long- 
horned  "  beetles  are  so  named  from  their  usually  well-developed, 
slender  antennae,  rarely  shorter  than  the  body,  and  often  several 
times  as  long.  They  are  usually  more  or  less  cylindrical,  often 
with  a  vertical  head,  and  always  with  well-developed  mandibles. 

The  larvae  are  wood-borers,  using  that  term  in  a  somewhat 
loose  sense  to  include  roots  and  the  more  solid  parts  of  a  few 
herbaceous  plants,  and  are  always  cylindrical,  the  segments  well 
marked,  those  immediately  behind  the  head  considerably  enlarged, 
while  anally  they  often  taper  quite  abruptly.  They  are  known  as 
' '  round-headed ' '  borers  to  distinguish  them  from  the  ' '  flat- 
headed  "  larvae  of  the  Buprcstidcr,  and  the  jaws,  though  rather 
small,  are  powerfully  developed,  fitted  for  cutting  the  hardest 
wood-fibre.  In  food  habits  the  insects  vary  greatly,  some  attack- 
ing only  dead  or  dying  tissue,  while  others  infest  sound  trees 
only.  Perhaps  in  most  cases  they  do  best  in  somewhat  weakened 
trees  which  their  ravages  soon  kill  entirely. 

Among  our  largest  species  are  the  Prionids  in  which  the 
margin  of  the  thorax  is  thin,  sharp,  and  often  toothed,  and  our 
most  common  species,  extending  over  a  large  part  of  the  United 
States,  is  Orthosoma  bninneum,  an  oblong,  somewhat  flattened, 
brown  species,  from  one  and  one-half  to  two  inches  or  more  in 


2o6 


AN   ECONOMIC   ENTOMOLOGY. 


length.  It  is  not  economically  important,  unlike  the  "broad- 
necked  Prionus,"  P.  laticollis,  whose  larvae  in  blackberry  are 
known  as  "giant  root-borers."  The  beetle  is  black,  robust, 
broader  than  usual,  with  a  broad,  toothed  thorax,  and  from  one 
to  two  inches  in  length.  The  larvae  are  immense,  nearly  three 
inches  for  a  full-grown  female,  and  they  feed  in  the  roots  of  a 


Fig.  195. 


The  "  giant  root-borer,"  Prionus  /a/t'coNis.—  'La.rva,  pupa,  and  adult. 

variety  of  trees  and  plants,  including  chestnut,  oak,  cherry,  apple, 
grape,  and  blackberry.  They  require  three  years  to  reach 
maturity,  and  are  sometimes  decidedly  troublesome.  There  is  no 
way  of  reaching  the  larvae  except  to  dig  them  out,  and  in  black- 
berry fields  the  sudden  wilting  of  part  or  all  of  a  hill  indicates 
almost  infallibly  the  presence  ol  one  or  more,  which  should  then 
be  found  and  destroyed  at  once.  Grape  and  apple  stand  the 
injury  better,  but  when  a  tree  becomes  badly  infested  nothing 
remains  but  to  take  it  out  and  burn  it.      Even  large  trees  are 


THE    IXSECT    WORLD. 


207 


Fig.  196. 


Phymatodrs  aiiitriins :  pupa  and  adult. 


sometimes  killed,  an  o\d  cherry-tree,  fully  eighteen  inches  in 
trunk  diameter,  which  died  rather  suddenly,  having  the  roots 
absolutely  riddled  in  every  direction  by  a  dozen  or  more  of  these 
immense  creatures. 

The  species  of  Phymatodes  are  much  smaller,  a  little  flattened, 
with  an  oval  thorax  and  a  tendency  to  blue  and  yellow  colors. 
The  larvae  feed  only  in  dead  or 
dying  wood  :  P.  anicenus,  a  bright 
blue  species  with  yellow  thorax, 
attacking  dead  shoots  of  grape, 
while  P.  varius  and  P.  variabilis 
live  under  the  bark  of  oak  cord- 
wood.  The  beetles  appear  in 
spring  and  lay  their  eggs  in 
dying  wood  or  in  wood  cut 
during  the  winter,  often  in  such 
numbers  that  the  bark  is  com- 
pletely loosened  by  the  larvae  and  will,  next  spring,  slip  off  in 
its  entirety.  They  are  hence  called  "bark-slippers"  by  wood- 
men. In  the  Southern  States  they  infest  tan-bark,  sometimes 
injuring  it  considerably.  Cutting  the  trees  during  the  summer, 
after  the  beetles  have  disappeared,  or  very  early  in  fall  will  put 
the  bark  and  wood  in  such  condition  that  it  will  not  be  attractive 
the  season  next  following. 

The  species  oi  Elaphidion  are  narrow,  brown  beetles,  covered 
with    whitish,    somewhat   mot- 
tled pubescence,  and  ha\'e  long  r\G.  197. 
and     rather     stout     antennae. 
They    are    known    as    "  oak- 
pruners,"    because    the    larvae 
of   several    species    bore    into 
twigs  and  branches  of  oak  and, 
when  nearly  full  grown,  girdle 
them  from   the   inside,  so  that 
the    first    high    wind    of    early 
winter  breaks  them  off,  carry 
ing  the  larvae  to  the  ground. 
Transformation  is  completed  in  the  June  or  July  following.    Often, 
during  late  summer,  the  wilting  of  a  twig  or  small  branch  indi- 


The  oak-piuiier,  Elaphidiuii  f<ai  allclum. 
—  a,  larva  ;  b,  pupa  in  its  burrow  ;  c,  beetle  ; 
kk,  cut  ends  of  the  twig ;  d  to  /,  structural 
details. 


AN   ECONOMIC    ENTOMOLOGY. 


Fig.  198. 


cates  the  presence  of  such  a  larva.  Apple-trees  are  sometimes 
attacked,  and  the  best  measure  for  general  adoption  is  the  sys- 
tematic gathering  and  burning  of  all  fallen  twigs  and  branches 
during  the  winter.  The  insects  are  not  confined  to  terminal 
branches  only,  but  sometimes  attack  the  trunks  of  young  shoots 
or  trees  after  a  fire  has  been  over  the  ground  and  scorched  them, 
and  in  such  cases  the  larvae  make  no  effort  to  girdle. 

In  the  genus  Cyllene  we  have  moderate-sized  species  that 
are  dark  velvety  brown  or  blackish,  with  bright  golden-yellow 
bands.  Of  these,  C.  pidus  infests  hickory  not  uncommonly, 
and  appears  in  spring,  while  C.  robinice  infests  the  locust,  and 
appears  in  fall.  This  latter  is  a  serious  pest,  and  makes  growing 
locusts  simply  impossible  in  many  localities.  As  soon  as  a  tree 
attains  a  moderate  size  it  is  riddled  with  the 
large  holes  made  by  the  larvae,  and  leads  but 
a  sickly  life  for  a  few  years  thereafter,  event- 
ually dying  down  to  the  ground.  The 
beetles  themselves  frequent  the  flowers  of 
golden-rod,  and  may  be  collected  there  in 
great  numbers,  the  females  resorting  to  the 
locusts  only  when  ready  to  oviposit.  An 
allied,  yet  larger  and  prettier,  species,  Pla- 
gionotus  speciosus,  bores  into  maple,  but 
is  usually  somewhat  rare  and  has  not  proved 
injurious  until  very  recently  in  some  parts  of  New  Hampshire, 
where  certain  shade-trees  suffered. 

We  sometimes  find  a  small  larva  belonging  to  this  series  boring 
into  the  branches  and  smaller  shoots  of  currant- 
bushes,  and  early  in  spring  these  change  to  a 
small,  brown,  somewhat  flattened  beetle,  rarely 
exceeding  one-quarter  of  an  inch  in  length, 
clothed  with  white  hair  grouped  to  form  two 
white  spots  towards  the  end  of  the  wing-covers. 
This  is  the  Psenocorjis  supernotatus,  which  is 
occasionally  abundant  enough  to  be  troublesome. 
It  can  be  held  in  check  by  close  pruning  during 
the  winter,  the  cuttings  to  be  burnt  before  spring 
opens  to  destroy  the  contained  larvae. 

In  late  spring  or  early  summer  some  of  the  terminal  shoots 


Plagionotus  speciosus. 


F"lG.  199. 


American  cur- 
rant-borer, Pseno- 
corus  supernotatus , 
enlarged. 


THE    IiYSF.CT    IVOKI.D. 


209 


of  applc-trces  may  suddenly  wilt  and  the  leaves  become  brown 
and  dry,  the  fruit,  if  any,  dropping  to  the  ground.  These 
wilted  shoots  will  be  found  hollowed  out,  and  the  culprit  is  the 
larva  of  another  little  brown  longicorn,  about  one-quarter  of  an 
inch  in  length,  (juite  robust  and  cylindrical,  the  wing-covers  a 
little  mottled  with  rather  long,  pale  hair.  It  is  a  species  of 
Eupogonius  which  has  not  figured  much  in  economic  literature, 
because  its  injuries  rarely  amount  to  more  than  a  light  summer 
pruning.  On  smaller  trees  the  infested  shoots  can  be  cut  and 
destroyed  and  on  larger  trees  careful  winter  pruning  is  indicated. 
A  well-known  orchard  pest  is  the  round-headed  apple-borer, 
the  larva  of  the  Sapcrda  Candida.      It  attacks  quince  in  prefer- 


FiG.  200. 


U  ^ 


C  h 

Round-head  apple-borer,  Saperda  Candida. — a,  larva  ;  b,  pupa;  c,  adult. 


ence  even  to  apple,  but  is  more  rarely  found  in  pear.  The 
beetle  appears  late  in  June  or  early  in  July,  depending  somewhat 
upon  latitude,  and  lays  its  eggs  on  the  trunk,  as  near  to  the  surface 
of  the  ground  as  possible,  under  a  loose  bark-scale  or  in  a  little 
hole  gnawed  by  its  mandibles.  The  larva  lives  for  a  year  in  the  sap 
wood,  then  bores  into  the  trunk,  up  or  down,  sometimes  some 
distance  below  the  surface,  and  in  the  spring  of  the  third  year 
changes  to  a  beetle.  Trees  of  quite  large  size  are  killed  in  a 
very  few  years,  and  for  some  time  before  are  sickly  and  do  not 
properly  mature  a  crop  of  fruit.  All  sorts  of  remedies  and 
devices  have  been  proposed,  cutting  out  the  larvae  being  the  one 
most  relied  upon  even  yet.  This  means,  in  many  cases,  making 
an  additional  large  wound  in  the  tree,  and  sometimes  the  remedy 
is  worse  than  the  disease.     The  best  method  of  protection,  and 

14 


AN  ECONOMIC  ENTOMOLOGY. 


Fig 


this  applies  as  well  to  other  species  infesting  tree-trunks, — e.g., 
the  locust-borer, — is  mechanical,  the  trunk  being  covered  or 
coated  by  some  material  impenetrable,  repellent,  or  destructive 
of  or  to  the  adults,  thus  preventing  oviposition.  The  most 
satisfactory  and  lasting  measure,  all  things  considered,  is  cover- 
ing the  lower  portion  of  the  trunk  with  wire  mosquito-netting, 
tying  at  the  top  and  hilling  up  against  it  at  the  bottom.  The 
netting  should  extend  at  least  two  feet  up  the  trunk  and  above 
that  a  coat  of  whitewash  should  be  maintained  during  the  danger 
season.  Other  measures,  equally  useful  here,  have  been  already 
referred  to  when  speaking  of  the  "  flat-headed  borers." 

In  the  genus  Oncideres  we  find  a  curious  and  interesting  egg- 
laying  habit  :  the  beetle  lays  an  ^^^  in  a  twig  or  branch,  and 
then  girdles  it  at  a  little  distance  below,  eating 
so  far  through  that  a  high  wind  brings  it  down. 
The  twig  wilts  at  once  and  the  wood  is  then  in 
the  exact  condition  desired  by  the  larva,  which 
\  '^^L  ^  undergoes  its  transformations  undisturbed  by 
growth  or  undesired  moisture.  Sometimes 
shade-trees  are  attacked  ;  but  merely  gathering 
and  burning  the  fallen  wood  keeps  the  insects 
in  check. 

There  are  many  other  longicorns  in  our  fauna, 
nearly  six  hundred  species  being  listed  in  the 
catalogues,  and  many  are  beautiful  as  well  as 
interesting.  The  few  species  referred  to  here 
do  not  even  illustrate  all  the  different  types, 
but  are  all  that  are  sufficiently  injurious  to  be 
referred  to  at  any  length.  Wooded  regions 
furnish  the  greatest  variety  of  species,  and  all 
portions  of  the  trees  furnish  support  for  their 
larvae. 

The  family  Chrysomelidcs,  or  leaf-beetles,  contains  species 
that,  in  the  main,  feed  upon  leaf-tissue  in  the  larval  as  well  as 
adult  stages,  and  many  of  them  attack  cultivated  crops.  The 
beetles  may  be  distinguished  by  the  tarsal  structure  already 
described,  by  their  usually  moderate  or  small  size,  short  antennae 
which  are  not  situated  on  frontal  prominences,  and  by  their 
usually  margined,   not  cylindrical  prothorax.     The  larvae  vary 


The  "twig-gird- 
ler,"  Oncideres  cin- 
gulatus. — a,  beetle 
at  work  ;  b,  egg- 
puncture ;  c,  gird- 
ling done  by  beetle ; 
c,  egg. 


l-'lC.    2()I. 


Wciik  111  llic  Kiiiiul-lK'.ul  applc-borci  ,  Sapt'xfa  nunlnla.  a.  iiiiiicHiic  in  wliich  t);.i; 
is  laid  ;  />.  same  in  sci  lion  :  r,  luilc  from  wliich  l>citlc  lias  finer>;e(l  ;  /,  same  in  section  ; 
.(Tt  pujia  ill  its  cell. 

1-"|C..    2CJ2. 


Work  of  the  locust-borer,  Cyllenc  robitiiu:. 


rilK    INSECT    WORLD. 


Fig.  204. 


considerably  in  form  and  habit,  but  are  often  more  or  less  viscid, 
and  are  then  termed  slugs. 

Belonging  to  the  genus  Lema  is  a  little  series  of  species,  several 
of  which  feed  upon  the  potato,  and  of  these  the  best  known  is 
the  Lema  j-Iincata,  or  "  3  lined  potato-beetle."  It  is  yellow  in 
color,  the  head  and  thorax  much  narrower  than  the  body,  and 
the  wing-covers  have  three  broad,  black  stripes.  It  is  rarely 
abundant  now-a-days,  though  at  one  time  a  somewhat  important 
species,  and  it  may  be  easily  controlled  by  the  use  of  the  arsenites. 
In  fact  it  is  the  treatment  adopted  for  the  better-known  "Colo- 
rado "  beetle  that  has  in  a  large  measure  exterminated  the  Lema. 

Somewhat  allied  in  form  are  two  species  of  Crioceris,  both 
feeding  on  asparagus,  and  both  introductions  from  Europe.  The 
common  "asparagus-beetle,"  C.  asparagi,  is  about  one-fourth 
of  an  inch  in  length,  the  wing-covers  black  with  red  or  yellow 
markings,  the  thorax  red  with  black  dots.  It  hibernates  as  an 
adult,  and  appears  early  in  spring,  eating  into  the  asparagus 
shoots  and  laying  its  eggs  upon  them. 
These  eggs  are  black  and  quite  long,  cylin- 
drical, set  on  end  so  as  to  project  from  the 
shoots  in  every  direction.  The  larvae  hatch 
soon  thereafter,  and  are  slimy,  greenish 
slugs,  with  black  dottings,  a  blackish  head, 
and  black  legs.  They  often  do  great  in- 
jury, particularly  on  young  plants.  On 
beds  where  cutting  is  done,  a  few  shoots 
should  be  allowed  to  grow  as  traps  during 
the  cutting  season,  and  on  these  the  ma- 
jority of  beetles  will  oviposit.  In  a  week 
they  should  be  cut  and  destroyed,  other 
shoots  being  allowed  to  take  their  place,  to 
be  similarly  treated  thereafter.  If  this  prac- 
tice is  kept  up  for  a  month,  no  injury  need 
be  anticipated  later  on,  as  the  species  will 
be  too  much  reduced  in  numbers  to  be- 
come troublesome.  No  volunteer  aspara- 
gus should  be  permitted,  as  otherwise  the  insects  will  multiply 
there.  In  young  beds  the  beetles  cannot  be  checked,  because 
spraying  the  feathery  leaves  is  impracticable,  but  after  the  larvae 


Asparagus-beetle,  Crio- 
ceris asparagi:  larva, 
adult,  and  shoot  with  eggs. 


212  AN   ECONOMIC  ENTOMOLOGY. 

develop,  they  may  be  readily  brushed  off  with  a  stick  in  the 
middle  of  a  hot  day  and  few  of  them  ever  get  back,  a  short 
period  on  the  hot  soil  proving  fatal.  The  work  can  be  done 
very  rapidly,  and  is  needed  two  or  three  times  only  to  secure 
entire  protection.  Where  a  field  of  old  shoots  becomes  badly 
infested  by  larvae,  much  benefit  may  be  derived  by  a  thorough 
dusting  with  fresh,  dry  slacked  lime  early  in  the  morning  while 
the  plants  are  yet  a  little  moist  with  dew.  The  lime,  if  properly 
prepared,  is  sufficiently  caustic  to  burn  holes  into  and  kill  the 
slimy  larvce.  As  new  specimens  are  constantly  hatching,  this 
dusting  must  be  done  several  times  at  short  intervals,  but  is  sure 
to  prove  effective  if  thoroughly  carried  out. 

The  "  1 2-spotted  asparagus  beetle,"  C.  12-punctatus,  is  some- 
what larger  and  more  robust,  uniformly  reddish  in  color,  with 
twelve  black  spots  on  the  wing-covers.  It  is  as  yet  less  common 
than  its  ally  and  not  so  widely  distributed,  but  may  be  treated  in 
much  the  same  way. 

The  species  of  Fidia  are  robust,  rather  long-legged  creatures, 
covered  with  short  hair,  giving  them  a  more  or  less  marked  gray 
appearance,  and  they  feed  largely  upon  grape.  Fidia  viticida 
has  proved  locally  injurious  in  Ohio,  and,  as  the  species  occurs 
over  a  large  portion  of  our  country,  it  may  break  out  anywhere 
at  almost  any  time.  The  beetle  feeds  upon  the  foliage,  eating 
irregular  holes  on  the  upper  surface  in  June.  Eggs  are  laid  on 
the  trunk  of  the  vine  or  on  the  branches  in  any  available  crevice, 
and  the  larvae  drop  to  the  ground  when  hatched,  making  their 
way  beneath  it  as  best  they  may,  to  the  rootlets  upon  which  they 
feed.  Remedial  measures  have  not  as  yet  proved  very  satisfac- 
tory, but  spraying  with  a  strong  arsenical  mixture,  using  lime  to 
avoid  burning  the  foliage,  will  kill  many  of  the  beetles.  Culti- 
vating the  ground  so  as  to  have  a  loose  powdery  top  soil  without 
crevices  leading  to  the  roots,  which  should  also  be  covered  as 
deeply  as  possible,  will  prevent  many  of  the  larvae  from  reaching 
their  feeding  place. 

Strawberry  plants  are  sometimes  injured  by  whitish  larvae 
feeding  upon  the  roots,  and  from  these  are  produced  small,  shin- 
ing, black  or  brownish  beetles  belonging  to  Paria  aterrima,  or 
certain  allied  species  popularly  known  as  ' '  strawberry  root- 
borers."     The  best  measures  here  are  clean  culture  and  frequent 


THE    INSECT   WORLD. 


213 


chancre  of  location  for  the  strawberry  beds.  The  insects  are 
rarely  troublesome  in  the  Eastern,  but  often  injurious  in  the 
Central  States.  Old  beds  should  be  ploughed  out  and  destroyed 
as  soon  as  they  have  been  picked,  and  when  new  beds  are  set  out 
care  should  be  used  in  selecting  plants  free  from  insect  attack. 
Where  a  two-year  picking  rotation  is  used  and  the  old  plants  are 
immediately  destroyed,  the  species  are  not  able  to  increase  ex- 
cessively.    The  arsenites  may  be  satisfactorily  used  to  kill  thi 

Fig.  205. 


Grape-root-worm,  Fidia  viticida.—A,  adult;  B,  pupa;    C,  larva;  the  other  letters  refer 
to  details  of  larval  structure. 


adults  when  they  are  noticed  feeding  upon  the  foliage.  Using 
commercial  fertilizers  instead  of  barn-yard  manure  is  also  to  be 
recommended. 

Perhaps  the  best-known  species  of  this  family  is  the  "  potato- 
bug,"  or  "potato-beetle,"  or  "  lo-lined  beetle,"  or  "Colorado 
potato-beetle,"  Doryphora  lo-lineata.  No  description  of  this 
insect  is  necessary,  the  figures  serving  to  illustrate  all  its  stages 
sufficiently  well.  The  insects  winter  underground  as  adults  or 
pupae,  and  the  beetles  emerge  early  in  spring,  attacking  the 
young  plants  as  soon  as  they  show  above  ground,  and  laying 
eggs  for  the  livid-reddish  larv^.  About  midsummer  these  have 
matured  a  second  brood  of  beetles,  and  a  second  brood  of  larvae 


214 


AN  ECONOMIC  ENTOMOLOGY. 


follows  shortly  thereafter,  resulting  in  a  fall  supply  of  beetles, 
which,  as  a  rule,  hibernate.  Sometimes  a  third  partial  brood  of 
larvae  reaches  the  pupal  state,  and  hibernates  in  that  condition. 
The  arsenites  are  well-known  and  approved  remedies,  used  at  the 
rate  of  one  pound  in  from  seventy-five  to  one  hundred  gallons 
of  water,  and  several  machines  especially  intended  for  spraying 
potato-fields  are  on  the  market.  The  insect  maintains  itself 
unchecked,  because,  while  active  war  is  waged  against  the  first 

Fig.  206. 


The  Colorado  potato-beetle,  Doryphora  lo-lineaia.—a,  a,  egg  patches  ;  b,  b,  b,  larva  in 
difterent  stages  of  growth  ;  c,  pupa;  d,  beetle;  e,  its  elytra  enlarged. 

brood,  little  attention  is  paid  to  the  second,  and  this  is  usually 
allowed  to  mature  and  provide  for  a  new  crop  the  year  following. 
Spraying  should  be  done  first  as  soon  as  the  beetles  begin  feed- 
ing, to  prevent  oviposition  if  possible  ;  it  should  be  done  a  sec- 
ond time  when  larvae  appear  generally,  and  it  should  be  done  as 
often  thereafter  as  beetles  or  larva  are  noticed  infesting  the 
plants. 

The  species  of  Diabrotica  are  rather  slender,  with  long  an- 
tennae ;  of  a  green  or  yellow  color,  with  black  spots  or  stripes. 
The  adults  feed  on  leaves,  flowers,  or  pollen,  but  the  larvae,  which 
are  white  and  slender,  usually  feed  in  the  roots  or  stems  of  plants. 
One  of  our  most  common  forms,  D.  vittata,  is  known  as  "  the 
striped  cucumber-beetle,"  and  is  yellow  with  black  stripes  on  the 


THE    IXSECT   WORLD.  215 

wing-covers.  It  feeds  on  all  kinds  of  cucurbit  vines,  and  on 
many  other  plants  as  well,  doing  injury  by  eating  into  the  stem 
of  the  young  shoots  at  or  below  the  surface,  where  it  has  a  ten- 
dency to  hide  during  the  middle  of  the  day.  The  larvae  live  in 
the  main  roots  underground,  making  short  galleries,  which,  if 
numerous,  weaken  or  even  kill  the  plant.  The  beedes  winter  as 
adults.  A  free  use  of  tobacco  dust  around  young  vines  or  other 
injured  plants  is  usually  protective,  though  in  some  localities  the 
farmers  resort  to  "  driving."  They  do  this  before  the  middle  of 
the  day,  sowing  air-slacked  lime  with  the  wind,  and  this  seems 
to  be  sufficiendy  offensive  to  the  insects  to  induce  them  to  leave 
for  fields  to  the  leeward,  where  they,  of  course,  become  doubly 
injurious  unless  also  driven  off.  Planting  an  excess  of  seed  to 
distribute  the  injury  is  a  common  practice,  and  so  is  starting  the 
plants  in  baskets  and  setting  them  out  when  well  established  and 
able  to  resist  injury.  Melon  and  other  cucurbit  vines  should 
always  be  plowed  out,  raked  up,  and  destroyed  as  soon  as  pos- 
sible after  the  crop  is  off,  to  destroy  any  larvae  that  may  be  then 
in  the  roots. 

An  allied  and  equally  common  species,  feeding  as  an  adult 
upon  a  great  variety  of  plants,  is  the  D.  i2-piinctata,  or  "12- 
spotted  Diabrotica. ' '  This  is  somewhat  larger  than  the  preced- 
ing, with  a  more  oval  body,  and  has  twelve  black  spots  on  the 
greenish-yellow  wing-covers.  The  larva  feeds  on  the  roots  of  a 
variety  of  plants  and  becomes  injurious  to  corn  in  the  Southern 
States.  There  are  two  broods,  and  the  beetles  winter  in  the 
adult  stage.  No  direct  remedy  is  known,  but  good  cultivation 
and  a  liberal  application  of  stimulating  fertilizers  is  advisable  to 
enable  the  corn-plant  to  resist  and  outgrow  attack.  Clean  cul- 
ture is  the  greatest  essential,  and  this  of  itself  will  do  much  to 
reduce  injury. 

The  ' '  corn-root  Diabrotica' '  of  the  Western  and  Central 
States  is  of  a  uniform,  pale-green  color,  named  D.  longicornis, 
from  its  long  antennae,  and  its  larva  has  proved  a  serious  pest  to 
corn.  The  complete  life  history  of  the  insect  is  known,  and  as  it 
winters  in  the  o.^^  state  in  corn-fields,  simple  rotation  is  all  that 
is  necessary  to  destroy  the  species.  It  can  never  become  injuri- 
ous unless  corn  follows  corn  year  after  year,  and  even  a  single 
year  rvithout  corn  serves  to  completely  rid  a  field  of  the  pest. 


KiG.  209. 


Fig.  210. 


Fig.  207,  Lenia  Irilineata.     Fig.  208,  a,  a,  larva;  ;  c ,  pupa  ;  d,  eggs  of  Lema  IriUneata. 
Fig.  209,  Diabroiica  12-punctata:  a,  egg;  b,  larva;   c,  injury  in  corn-stalk;  d,  pupa; 
e,  beetle.     Fig.  210,  Diabrotica  longicornis :  a,  adult ;  b,  pupa  ;  c,  larva  ;  d,  same  in  its 
case.     ¥\g. -211,  Diabroiica  vitlata.     Fig.  212,  larva  of  same.     Fig.  213,  its  pupa. 
216 


THE    INSECT   WORLD.  217 

The  genus  Galcrnca  contains  a  series  of  rather  small,  oblong 
species,  mostly  dirty  clay-yellow  in  color,  and  more  or  less  black 
marked  or  spotted.  Of  these  none  is  more  troublesome  than  the 
"  elm-leaf  beetle,"  Galcnica  xautlioweUcna,  which  is  another  of 
our  undesirable  imp(,)rtations  from  Europe.  It  is  rather  greenish 
yellow  when  fresh,  with  two  black  stripes  on  the  wing-covers. 
It  hibernates  as  a  beetle  wherever  it  can  find  shelter,  and  attacks 
the  leaves  of  elms  in  spring  as  soon  as  they  are  well  grown, 
eating  irregular  round  holes,  so  they  soon  look  as  if  loads  of 
shot  had  been  fired  through  them  in  every  direction.  The  yel- 
low, bottle-shaped  eggs  are  laid  in  double  rows  on  the  under 
sides  of  the  leaves,  and  from  them  hatch  the  yellow,  black-spotted 
larvae,  covered  with  little  bristly  tufts  of  hair.  In  the  northern 
part  of  its  range,  including  the  red  shale  of  New  Jersey,  a  single 
brood  is  normal,  but  south  of  this,  and  including  an  extension 
into  Long  Island,  the  insect  has  two  broods  annually,  and  at 
Washington  or  further  south  may  have  three  or  even  more.  As 
against  these  insects  the  arsenites  are  effective,  and  the  trees 
should  be  sprayed,  preferably  with  the  arsenate  of  lead,  just  as 
soon  as  the  beetles  begin  feeding.  The  object  is  to  destroy  as 
many  of  the  hibernating  forms  as  possible,  and  to  prevent  egg- 
laying  in  large  part.  A  second  spraying  should  be  given  when 
the  eggs  begin  hatching,  to  destroy  the  young  larvae,  and  in 
serious  cases  a  third  spraying  a  week  or  ten  days  thereafter  will 
be  beneficial.  When  the  larvae  are  full  grown  they  descend  the 
trunk  to  the  ground,  where  they  change  to  bright-yellow  pupae 
among  the  grass  or  rubbish  on  the  surface.  Here  they  may  be 
destroyed  by  hot  water,  kerosene,  strong  soap-suds,  lime,  or 
other  suitable  substances,  and  the  second  brood,  where  such 
occurs,  may  thus  be  materially  lessened.  Where  there  are  two 
broods  or  more,  repeated  .sprayings  will  be  necessary,  extending 
throughout  the  summer.  If  these  methods  are  generally  adopted 
the  insect  can  be  satisfactorily  controlled.  Protecting  a  few  trees 
only  among  many  that  are  neglected  will  always  be  difficult  and 
can  be  at  best  only  partly  successful.* 

*  For  detailed  information  concerning  the  treatment  of  trees  in  cities 
or  towns,  or  on  a  large  scale,  the  publications  of  tlie  United  States  De- 
partment of  Agriculture  and  of  the  New  Jersey  Experiment  Station 
should  be  consulted. 


2l8 


A2V   ECONOMIC  ENTOMOLOGY. 


S«, 


THE    INSECT   IVOKLD.  219 

Distinct  from  all  the  forms  hitherto  mentioned  are  the  "flea- 
beetles,"  so  called  because  of  their  greatly  enlarged  hind  femora, 
giving  them  the  power  of  making  sudden  leaps  ending  in  flight. 
We  have  many  sjiccies,  and  some  of  them  are  decidedly  injurious 
and  troublesome  to  deal  with. 

The  grape  flea-beetle  is  a  well-known  species  called  Haltica 
chalybca,  from  its  steel-blue  color,  and  it  feeds  both  as  adult  and 
larva  on  the  leaves  of  the  grape.  The  larvae  are  blackish  and 
slender,  slug-like  and  somewhat  viscid,  feeding  in  company 
during  a  great  part  of  their  growth.  They  are  easily  controlled 
by  any  stomach  poison,  and  the  Bordeaux  mixture,  applied  as  a 
fungicide,  seems  to  be  effective  in  keeping  them  in  check. 

The  genera  Crepidodera  and  Epitrix  contain  a  number  of 
small  species,  among  which  the  "cucumber  flea-beetle,"  or 
' '  potato-flea, ' '  Epitrix  accumeris,  easily  ranks  first.  As  a  small 
black  beetle,  it  eats  little  round  holes  into  the  leaves  of  potato, 
tomato,  egg-plant,  and  a  variety  of  other  solanaceous  plants,  as 
well  as  into  those  of  melon,  cucumber,  and  other  cucurbitaceous 
vines.  Potatoes  seem  rather  the  favorite  food,  and  where  the 
beetles  and  their  little  holes  are  numerous  the  leaves  turn  brown 
and  die,  checking  the  growth  of  the  plant,  and  hence  of  the 
crop.  The  larvae  are  leaf-  and  stem-miners,  but  do  little  or  no 
damage.  Usually  Paris-green  and  London-purple  are  satisfac- 
tory remedies,  and  it  has  been  observed  that  the  Bordeaux  mix- 
ture acts  as  a  deterrent  when  liberally  used,  serving  thus  the 
double  purpose  of  checking  insect  injury  and  plant  disease. 
Tobacco  is  also  a  very  satisfactory  material  used  as  a  decoc- 
tion, but  is  scarcely  economical  except  on  a  small  scale  or  in 
gardens. 

The  "sweet-potato  flea,"  Ch(£tocnema  conjinis,  is  an  inter- 
esting, if  troublesome,  small,  bronzed  beetle,  attacking  the  leaves 
of  the  young  plants  just  after  they  have  been  set  out,  and  eating 
little  channels  along  the  veins,  finally  making  the  net-work  so 
complete  that  the  leaves  shrivel  and  dry.  If  the  vines  get  a  fair 
start,  they  outgrow  the  injury  very  rapidly,  but  cold,  wet  weather, 
by  retarding  growth,  sometimes  enables  the  insects  to  kill  them. 
Dipping  the  plants  before  they  are  set  out  in  the  arsenate  of  lead 
mixture,  at  the  rate  of  fifteen  ounces  to  fifty  gallons  of  water,  will 
prove  a  satisfactory  protection  without  danger  of  injury  to  the 


Fig.  217. 


Fig.  219. 


Fig.  217,  grape  flea-beetle,  Haltica  chalybea,  in  all  its  stages,  on  a  grape  slioot.     Fig. 
218,  work  of  the  sweet-potato  flea  on  the  leaves.     Fig.  219,  pale-striped  flea-beetle,  Sys- 
tena  blanda.    Fig.  220,  the  rosy  Hispa,  Odontota  rosea. 
220 


THE    INSECT    WORLD. 


plants.     Or  they  may  l^e  thoroughly  sprayed  with  the  Bordeaux 
mixture  immediately  after  being-  set  out. 

Of  somewhat  larger  size  and  more  slender,  graceful  form  are 
the  species  oi  Sysloia,  and  of  these,  6".  blanda,  the  "  pale-striped 
llea-beetle,"  has  become  best  known  by  reason  of  its  injury  on  a 
great  variety  of  plants,  including  sugar-beets.  As  with  the  other 
"fleas"  it  is  injurious  in  the  beetle  stage  only,  and,  as  a  rule,  in 
early  summer  on  young  plants.  I  have  seen  it  ruin  an  entire 
field  of  carrots,  and  have  found  it  on  melons,  potatoes,  beets,  and 
pig-weed  in  equal  abundance.  Its  life  history  has  not  been  pub- 
lished, but  its  larva  is  said  to  feed  upon  corn-roots.  This  is  cer- 
tainly not  universally  true,  and  its  native  food-plant  in  the  early 
stages  remains  to  be  ascertained.  As  with  otiier  leaf-feeding 
forms,  we  are  referred  to  the  arsenites,  or,  as  a  means  of  protection 
only,  to  air-slacked  lime,  which  will  drive  the  beetles  to  wild 
plants,  leaving  the  lime-dusted  crop  free. 

In  the  genus  Phyllotreta  we  find  another  series  of  small  species 
not  exceeding  one-eighth  of  an  inch  in  length,  ordinarily  black  in 
color,    with   yellow    stripes    or 

spots  on  the  wing-covers.    The  Fig.  221. 

most  common  species  in  the 
East  is  the  ' '  wavy-striped  flea- 
beetle,"  P.  vittata,  in  which 
there  is  a  distinct  yellow  stripe 
through  the  middle  of  each  ely- 
tron. The  adults  feed  upon  the 
leaves  of  cabbage,  radish,  mus- 
tard, and  others  of  the  cruciferae, 
while  the  larvae  live  as  miners 
in  the  tissues  of  the  same  plants. 
In  dealing  with  this  species 
the  important  points  are  clean 
culture  and  keeping  down  all 
cruciferous  weeds.  If  in  addi- 
tion all  crop  remnants  are  promptly  gathered  and  destroyed,  no 
serious  danger  need  be  apprehended. 

Following  the  flea-beetles  is  a  series  of  very  curious,  somewhat 
wedge-shaped  insects,  the  Hispida,  in  which  the  antennae  are 
thickenedf  and  the  elytra,  or  wing-covers,  broaden  to  the  tip, 


Striped  flea-beetle,  Phyllotieia 
a,  larva  ;  b,  adult. 


AlV   ECONOMIC   ENTOMOLOGY. 


where  they  are  rather  abruptly  terminated.  The  larvae  are  leaf- 
miners,  and  perhaps  the  most  common  species  is  the  Odo7itota 
dorsalis,  or  locust-beetle,  which  occurs  abundantly  on  the  leaves 
in  early  summer,  and  is  orange  in  color,  with  a  broad  black 
stripe  on  the  centre  of  each  elytron.  The  eggs  are  covered  with 
a  little  mass  of  excrement,  and  are  laid  singly,  few  leaves  con- 
taining more  than  two  or  three.  Not  much  real  injury  is  done 
by  any  of  the  species,  and  the  suggestion  that  the  adults  feed 
exposed  and  succumb  readily  to  the  arsenites  is  all  that  is  neces- 
sary on  the  subject  of  remedies. 

The  adult  Cassidce  are  called  "tortoise-beetles,"  or,  by  the 
sweet-potato  grower,  "golden  bugs."  They  are  characterized 
by  their  broad,  almost  quadrate  form,  flat  under  and  convex 
upper  side,  and  by  the  more  or  less  metallic-yellow  or  golden 
color  of  the  elytra  and  upper  surface  generally.  Most  of  the 
species  feed  upon  Convolvulus^  to  which  natural  family  the  sweet- 
potato  belongs,  and  the 
^^^-  ^^^'  latter  is  about  the  only  cul- 

tivated crop  suffering  from 
the  attacks  of  insects  of  this 
series.  The  beetles  hiber- 
nate and  appear  in  the  sweet- 
potato  fields  as  soon  as  the 
crop  is  set  out,  eating  irreg- 
ular holes  in  the  leaves,  and 
laying  their  eggs,  encased  in 
a  mass  of  excrement,  on  the 
under  surface.  The  larvae 
are  known  as  "peddlers," 
because  they  have  piled 
upon  a  pair  of  anal  forks  all 
the  cast  skins  and  a  part  of 
their  excrement,  forming  a 
sort  of  shelter,  umbrella,  or 
"pack,"  to  which  latter 
resemblance  they  owe  the 
common  name.  The  most  abundant  form  is  the  Cassida  bivittata, 
or  "two-striped  tortoise-beetle,"  so  named  from  the  two  black 
stripes  on  each  wing-cover.     Following  closely  is  the  Coptocycla 


Coptocycla  auiiclialcea. — a,  larvae,  or  ped- 
dlers, with  their  packs;  b,  larva  with  pack 
removed  ;  c,  pupa. 


T]IE    IXSECT   WORLD. 


223 


mirichalcca,  so  named  because  of  its  resemblance  to  a  drop  of 
molten  gold.  The  injury  is  done  by  these  species  just  after  the 
plants  are  set  out  and  before  they  get  a  start.  Where  the  season 
is  unfavorable  to  rapid  growth,  some  plants  may  be  killed,  but 
under  ordinary  conditions  they  are  soon  out  of  danger.  Good 
practice  is  to  set  only  large,  well-developed  plants,  or  to  dip 
everything  before  setting  out  in  the  arsenate  of  lead  mixture 
recommended  against  the  flea-beetles.  Finally,  it  has  been  found 
that  chickens  are  fond  of  the  insects  in  all  stages,  and  by  turning 
loose  a  sufficient  number  in  the  fields  after  the  plants  have  been 
set  out  practical  exemption  is  secured. 

The  bean-  and  pea- weevils  constitute  a  little  family  by  them- 
selves under    the  term  Bnichida.     They  agree  with   the   leaf- 
beetles   in   general   structure,    but 
have  a  small  head,  prolonged  into  ^'"^''  ^"-^^' 

a  blunt  snout,  a  very  obese  abdo- 
men, exposed  at  the  tip  by  the 
short,  square  wing-covers,  and 
much  enlarged  hind  legs,  which 
are  not  used  for  leaping.  They 
are  always  small  and  usually  more 
or  less  ashen-gray  in  color,  covered 

vi_        i."i"   u    1-    •  1  u*    u        Bean-weevil,    Biiiclius   fabcr,   much 

With  whitish  hair  or  scales,  which  ,       ,'  ■  <•  ,  ^  u 

'_  enlarged  ;  b,  an  infested  bean. 

form  variably  evident  markings  on 

the  wing-covers.  The  beetles  are  often  found  in  dried  seeds  of 
leguminous  plants, — peas,  beans,  lentils,  or  the  like, — and  are 
sometimes  seriously  injurious  in  the  stored  product,  lessening 
also  or  destroying  the  germinating  power.  The  beetles  come 
out  normally  in  the  spring,  and  after  pairing  the  females  lay 
their  eggs  in  the  young  pods  of  the  plants  affected  by  them. 
The  larvae  work  their  way  into  the  forming  seed  and  grow  very 
slowly,  the  species  varying  somewhat  in  the  details  of  their  life 
history.  Our  only  method  of  controlling  the  insects  is  in  the 
stored  product,  or  seed,  and  here  by  means  of  bisulphide  of  car- 
bon we  can  kill  larvae  as  well  as  adult  beetles,  in  any  moderately 
tight  receptacle.  The  rule  should  be,  gather  the  entire  crop  and 
allow  nothing  to  remain  in  the  field  ;  plant  only  sound  seed,  and 
never  under  any  circumstances  throw  away  "weevilly"  peas, 
beans,  lentils,  etc.     They  should  always  be  burnt,  or  otherwise 


V 


224 


A,V   ECONOMIC   ENTOMOLOGY. 


completely  destroyed.  Wild  as  well  as  cultivated  plants  are 
infested,  though  we  do  not  know  that  insects  infesting  our  garden 
varieties  are  carried  over  by  other  wild  species. 

Fig.  224. 


Fig.  225. 


'Pe^2L-\^zfi\\\,  Bruchus  pisi—c,  larva;    rf,  pupa;    (^,  adult ;  all  enlarged. 

We  now  reach  the  series  Hderomera,  or  beetles  in  which  the 
fore  and  middle  tarsi  have  five  joints,  while  the  posterior  are 
four-jointed  only.  We  have  rather  a  large  number  of  families, 
many  with  a  few  species  only,  and  as  a  whole  they  are  feeders 
in  or  on  decaying  or  dry  vegetable  tissue,  whether  herbaceous, 
woody,  or  fungoid  in  character.  There  are  exceptions,  of  course, 
but  that  is  the  rule. 

The  Tencbrionidce,  or  "darkling-beetles."  contain  species 
ranging  from  quite  small  to  very  large,  found  under  all  sorts  of 
conditions,  but  most  frequently  beneath 
bark  of  trees,  on  fungi,  or  under  stones, 
among  dry  vegetable  matter.  There  is 
no  uniformity  in  appearance,  but  in  most 
instances  the  antennae  are  more  or  less 
moniliform,  or  bead-like.  The  majority 
of  our  species  are  Western,  occurring  in 
their  greatest  variety  in  the  Rocky 
Mountain  region,  but  none,  so  far  as  I 
know,  trouble  green  vegetation.  The 
typical  genus  Tenebrio  contains  black  or 
brownish,  somewhat  flattened  species, 
with  a  square  thorax  and  deeply  ridged 
wing-covers.  The  larvae  are  known  as  "  meal-worms,"  and  feed 
upon  grain  or  meal  remnants  in  barn,  stable,  or  other  sheltered 


The  meal-worm,  Tenebrio 
molitor.—a,  larva  ;  b,  pupa; 
c,  adult;  d  to  h,  structural 
details. 


THE    IXSECT   WORLD. 


225 


spots.  They  are  often  bred  by  bird-fanciers  in  large  numbers, 
and  only  need  plenty  of  food  to  multiply  rapidly.  They  rarely 
do  serious  injury,  but  are  not  pleasant  to  have  around,  and  may 
be  easily  controlled  by  cleanliness,  supplemented  in  extreme 
cases  with  bisulphide  of  carbon.  A  few  other  small,  brown 
forms,  among  which  the  species  of  Triboliuni  may  be  mentioned, 
occur  under  like  circumstances,  but  are  amenable  to  the  same 
treatment. 

Fig.  226. 


Triboliuni  confusum. — a,  adult;   b,  larva;  c,  pupa;  e,  head,  with  antenna;  y,  same  of 

T.  fcnugincuiii. 

Perhaps  the  most  interesting,  and  economically  the  most  im- 
portant of  this  series,  are  the  "blister-beetles,"  or  IMcloida;. 
The  name  "blister-beetles"  is  from  a  peculiar  property  possessed 
hv  them  of  raising  blisters  on  the  human  i^kin.  This  is  due  to  a 
substance  called  "  cantharidin,"  found  in  the  juices  of  all  the 
species  to  a  greater  or  less  extent.  The  species  generally  used 
in  medicine  comes  from  Spain,  hence  the  insects  are  also  known 
as  "Spanish  flies."  The  beetles  are  rather  soft-bodied,  with 
broad  heads,  the  antennae  often  knotted  in  the  males,  the  thorax 
narrow  and  cylindrical,  the  wing-covers  extending  well  down  the 
i'ides.  Some  of  the  species  are  brightly  colored  and  banded, 
occasionally  metallic  bronze  or  coppery,  and  all  of  them  are  leaf- 
feeders.  Among  the  common  eastern  species  several  attack 
potatoes,  and  of  these  a  yellow  and  black-striped  form,  Epicaida 
viitata,   is  known  as  the  "old-fashioned    potato-bug."     Asters 

15 


Fig.  227. 


Meloidae,  or  "blister-beetles." — Fig.  227,  Spanish  fly,  Lytta  vesicatoria.  Fig.  228, 
Epicauta  vittata:  a,  second  larva;  c,  rf,  coarctata  larva,  from  back  and  side.  Fig.  229, 
a  and  b,  true  pupa  of  same,  from  side  and  front.  Fig.  230,  a,  grasshopper  egg-pod;  b, 
a  few  eggs  from  same  :  c.  triungulin  ;  rf,  carabidoid  larva  ;  e,  scarabidoid  larva.  Fig. 
231,  adult  Epicauta  vittata.  Fig.  232,  Epicauta  cinerea.  Fig.  233,  a,  Macrobasis  uni- 
color ;  b,  Epicauta  pennsylva>iica. 

226 


THE    INSECT    WORLD.  227 

and  other  flowers  are  injured  by  a  black  species  with  gray-edged 
elytra,  Epicauta  cinerca,  and  among  field-crops  beets  are,  after 
potatoes,  the  chief  sufferers.  The  beetles  appear  quite  suddenly 
in  large  numbers,  and  some  species  disappear  almost  as  quickly, 
while  others  linger  several  days.  A  uniformly  black  form, 
Epicauta  pcnnsvlvanica,  is  often  found  in  considerable  numbers 
on  the  flowers  of  the  golden-rod  in  August  and  September,  while 
a  uniformly  gray  species,  Macrobasis  unicolor,  is  common  on  the 
false  indigo. 

The  life  history  is  interesting,  and  the  species  may  be  divided 
into  two  series,  those  living  in  the  nests  of  burrowing  bees  and 
those  living  in  grasshopper  eggs.  In  the  first  series  the  eggs  are 
laid  on  flowers,  and  from  each  hatches  an  active  little  creature 
with  long  legs,  prominent  jaws,  and  large  head,  which  is  known 
as  a  "  triungulin."  It  runs  about  the  flowers  until  the  proper 
kind  of  bee  comes  along,  gains  a  foothold  on  this,  and,  buried 
among  the  hairy  clothing,  allows  itself  to  be  transported  to  the 
bee  nest.  There  it  quits  its  unconscious  host,  makes  its  way 
into  one  of  the  completed  cells,  devours  first  the  ^^'g  or  young 
larva,  and  then  completes  its  own  transformations,  feeding  upon 
the  stores  now  without  another  owner.  This  type  is  only 
indirectly  of  economic  interest,  but  is  rather  injurious  than 
otherwise. 

In  the  second  series  the  Qg<g  is  laid  either  on  a  plant  or  on 
the  ground,  but  in  either  case  a  triungulin  similar  to  that  above 
described  results,  and  this  has  the  power  of  existing  without  food 
for  several  days,  while  hunting  for  a  grasshopper  egg-pod.  When 
such  a  one  is  found  its  wanderings  are  over,  and  it  begins  feed- 
ing at  once.  When  it  moults  its  large  head  and  long  legs  disap- 
pear, and  it  resembles  a  Carabid  larva,  with  ovate  body,  small 
head  and  jaws,  and  short  legs  ;  it  is  now  in  the  ' '  carabidoid' ' 
stage.  Again  it  moults,  and  now  the  resemblance  is  to  a 
small  "white  grub,"  for  which  reason  this  has  been  termed 
the  "  scarabidoid"  stage.  When  all  the  grasshopper  eggs  are 
devoured,  our  larva  is  full  grown,  ceases  feeding,  and  shrinks 
into  its  own  hardened  skin,  forming  a  coarctate  stage,  or 
pseudopupa,  in  which  it  winters.  In  spring  it  emerges  from  this 
covering,  is  active  a  short  time  without  feeding,  and  then  enters 
the  true  pupal  stage,  in  which  it  resembles  other  Coleoptera.      In 


2  28  AN   ECONOMIC   ENTOMOLOGY. 

this  stage  it  remains  until  the  proper  conditions  occur,  and  then 
joins  its  companions  in  a  seemingly  concerted  movement  to  arise 
and  assume  the  beetle  stage.  This  uniformity  of  development 
explains  the  sudden  appearance  of  the  insects  in  large  numbers, 
and  their  power  to  cause  mischief  is  derived  from  it,  since  the 
farmer  does  not  often  realize  the  nature  of  the  invasion  until  con- 
siderable injury  has  been  done.  In  the  larval  stage  they  are 
beneficial,  in  so  far  as  they  feed  upon  the  eggs  of  grasshoppers, 
but  it  is  questionable  whether  this  benefit  overbalances  the  dam- 
age they  do  as  adults,  and  I  never  hesitate  to  advise  prompt 
measures  for  their  destruction.  The  best  of  these  is  a  thorough 
application  of  one  of  the  arsenites  as  soon  as  the  insects  appear, 
adding  milk  of  lime  to  make  the  poison  stick  better  and  to  dis- 
courage feeding.  In  small  patches  the  beedes  can  be  gathered 
in  pans  early  in  the  day,  or  they  may  be  driven  to  a  layer  of 
straw,  the  latter  to  be  set  on  fire  when  the  insects  become  en- 
tangled among  it.  The  last  is  the  least  desirable  of  the  measures, 
though  under  some  circumstances  very  effective.  In  all  cases, 
promptness  is  essential. 

The  Rhynchophora,  or  "snout-beetles,"  are  separated  into  a 
number  of  families  which  need  not  be  particularly  described  here, 
but  all  agree  in  having  a  more  or  less  evidently  produced  beak 
or  snout,  at  the  end  of  which  the  small  mouth  parts  are  situated. 
The  terms  "  curculios"  and  "weevils,"  in  addition  to  that  above 
given,  are  rather  indiscriminately  applied  to  species  of  this  series. 
All  the  snout-beetles  are  vegetable  feeders  in  both  larval  and 
adult  stages,  and,  therefore,  more  or  less  injurious.  Many  of  the 
larvae  are  internal  feeders,  and,  therefore,  white  or  yellowish, 
usually  with  short,  bristly  hair,  a  brown  head,  and  no  feet.  As 
a  rule,  they  are  somewhat  curved  and  terminate  rather  bluntly,  a 
little  like  "white  grubs,"  but  without  the  peculiar,  large,  ter- 
minal segment.  It  will  be  necessary  to  restrict  our  mention  to 
the  most  troublesome  forms,  and  the  first  of  these,  in  systematic 
order,  is  "  Fuller's  rose-beetle,"  Aramigus  fidleri. 

This  beetle,  which  has  a  short,  obtuse  snout,  and  is  of  a  dark, 
smoky  brown  color,  lays  its  eggs  in  little  masses  under  any  sort 
of  shelter  on  rose-bushes,  and  the  resulting  white,  grub-like 
larvcC  feed  on  the  tender  roots  of  the  plants.  The  insect  is, 
essentially,  a  green-house  pest,  and  often  weakens  the  plants,  so 


THE    INSECT    irOK/./l 


229 


as  to  render  unprofitabk'  if  it  does  not  kill  tlum.  The  beetles 
are  long-lived,  and  hide  during  tiie  day  on  tin-  uiulcr  side  of  the 
leaves  on  which  they  feed.  Hence,  collecting  and  destroying 
them  is  the  most  satisfactory  remedy,  while  the  use  of  a  tobacco 
extract  on  the  ground  will  act  both  as  a  fertilizer  and  to  destroy 
the  subterranean  larvce. 

The  clover-leaf  beetle,  Phytoitoiiius  piDictatus,  is  another  (juite 
large  species,  dull  brown   in  color,  with  indefinitely  striped  wing- 

FiG.  234. 


Clover-leaf  beetle,  Phytonomus  puiictalus. — a,  egg;  b,  b,  larv;e  feeiiing;  c,  very  young 
larva ;  y,  cocoon,  its  net-like  character  shown  at  .?•  ,•  A,  pupa  ;  /,  beetle,  on  clover-stalk  ; 
k,  same,  enlarged  ;  other  letters  refer  to  structural  details. 


covers,  and  a  short,  stout  beak.  The  larva  is  green,  its  form  well 
shown  in  the  figure,  and  it  feeds  chiefly  at  night,  eating  irregular 
holes  in  the  leaves.  When  full  grown  it  forms  a  peculiar  net-like 
cocoon  at  or  a  little  beneath  the  surface  of  the  ground  and 
pupates,  becoming  adult  a  few  days  thereafter.  The  insects 
hibernate  in  the  larval  stage,  and  their  injury  becomes  manifest 


230 


AN   ECO  ATOMIC  ENTOMOLOGY. 


Fig.  235. 


Diseased 
larva  of  clover- 
leaf  beetle. 


quite  early  in  the  season,  often  threatening  entire  destruction  of 
the  crop  when  they  are  nearly  full  grown.  Fortunately,  nature 
has  provided  a  check  for  this  insect  in  a  fungous  disease  which  in 
most  localities  carries  off  the  larvae  annually,  just 
before  they  mature,  leaving  only  a  comparatively 
small  proportion  to  perpetuate  the  species.  As 
this  disease  seems  to  occur  in  seasons  of  all  kinds, 
and  irrespective  of  climatic  conditions,  it  can  be 
easily  introduced  into  any  locality  in  which  the 
insects  become  destructive.  Affected  larvae  curl 
themselves  round  a  spear  of  grass  or  on  the  edge 
of  a  leaf  and  die,  first  swelling  somewhat  and 
becoming  gray  in  color  ;  then  they  collapse  and 
become  black,  eventually  forming  a  small,  dried, 
black  mass,  utterly  indistinguishable  in  character. 
The  "white-pine  weevil,"  Pissodes  strobi,  is  one  of  the  most 
serious  enemies  to  that  tree,  and  in  the  more  northern  States 
attacks  the  leading  shoots,  in  young  trees  spoiling  their  shape 
completely.      The  insect  has  been  studied,   and  a  full  account 

is  given  in  the  Fifth  Report  of 
the  United  States  Entomological 
Commission,  dealing  with  forest 
insects,  but  no  satisfactory  reme- 
dial measures  are  proposed.  In 
parks  or  gardens  small  orna- 
mental trees  can  probably  be 
protected  by  keeping  the  leading 
shoots  sprayed  during  the  spring 
with  a  carbolated  soap-wash,  to 
which  Paris  green  has  been 
added  at  the  rate  of  one  pound  in  one  hundred  and  fifty  gallons 
of  water.  Other  infested  shoots  should  be  gathered  and  burnt. 
The  report  above  cited  is  so  full  on  the  subject  of  forest  insects 
belonging  to  this  series  that  only  those  infesting  cultivated  crops 
need  be  discussed  here. 

Early  in  the  season  we  find  on  the  leaves  and  stems  of  rhubarb 
a  rather  long,  cylindrical  weevil,  Lixus  co7icavus,  with  a  short 
heavy  snout,  entirely  covered  by  an  easily  rubbed  off,  rusty 
powder.      It  is  also  remarkable  for  its  exceedingly  firm  texture, 


Fig.  236. 


White-pine  weevil,  Pissodes  stiobi. — a, 
its  larva  ;  b,  its  pupa. 


THE    INSECT   WORLD. 


231 


Fig.  237. 


making  it  difficult  to  pierce  with  any  ordinary  pin.  It  bores 
little  holes  in  the  leaf  and  flower  stems  of  the  plant,  laying  an 
egg  in  each,  from  which  hatches  in 
due  time  a  white,  grub-like  larva, 
which  feeds  in  the  plant  tissue. 
Where  the  leaves  are  regularly  cut 
for  market,  little  trouble  is  experi- 
enced. All  old  leaves  not  needed 
by  the  plant  should  be  removed  and 
destroyed,  so  that  after  midsummer 
none  of  the  early  leaves  should  re- 
main on  the  plants.  If  this  practice 
is  constantly  carried  out  no  injury 
need  be  apprehended.  The  natural 
food-plant  is  said  to  be  dock. 

In    the    genus   Anthoiiomus   small 
species  predominate,  and  the  colors 
are  modest,   but  their  powers  of  in- 
jury are  by  no  means  in  proportion 
to  their  size.     One  of  the  most  trou- 
blesome is  the  "strawberry-weevil," 
A.  signatus,  which  appears  as  a  small,  blackish  beetle,  with  gray 
pubescence,  when  the  buds  are  developing,  and  lays  an  ^gg  in 
each,  afterward  puncturing  the  flower-stalk  be- 
low the  bud  so  as  to  check  development.    The 
larva  feeds  upon  the  pollen  in  the  unopened 
bud,   and    finds  it  sufficient  to   attain    its  full 
growth,  changing  to  a  beetle  in  midsummer. 
The  insect  attacks  a  number  of  other  flowers 
in  the  same  way,  not  even  confining  itself  to 
one   natural  family,  and    its  injury  to   straw- 
berries is  of  a  somewhat  intermittent  character, 
becoming  worse  for  a  number  of  years,  then 
stopping    suddenly   for    no   apparent    reason. 
Only  staminate,  or  pollen-bearing,  varieties  are 
attacked,  and  the   Sharpless  is,  perhaps,    the 
most  seriously  infested.     By  planting  chiefly 
pistillate  varieties,  the  staminate  rows  may  be  protected  by  cheap 
coverings  until  the  buds  are  ready  to  open,  and  even  if  a  small 


Rhubarb-beetle,  Lixus    concavus. 
—a,  its  larva  ;  b,  pupa. 


Fig.  2:,S. 


Strawberry-weevil, 
Anthonomus  sigtiatus- 


232 


AN  ECONOMIC  ENTOMOLOGY. 


crop  only  is  obtained  on  the  pollenizers,  the  main  crop  will  be 
safe  without  protection.  Insecticides  have  not  proved  markedly 
useful  in  this  case. 

Other  species  of  this  genus  have  proved  more  or  less  trouble- 
some,  notably  A.  quadri-gibbus ,  on  apple,    but   none  of  these 

Fig.  239. 


Work  of  the  strawberry-weevil.— a,  shoot  of  strawberry-plant  bearing  punctured 
buds,  b  ;  the  egg  at  c ;  larva  at  d;  pupa  at/,-  at^  an  open  strawberry-flower  showing 
the  holes  eaten  by  the  beetles. 

require  more  attention  here,  and  the  next  species  in  order  is 
Conotrachelus  nenuphar,  the  redoubtable  "  plum-curculio." 
Next  to  the  "codling-moth,"  this  is,  perhaps,  the  most  serious 
of  the  orchard  pests,  and  it  ranks  above  it  in  the  difficulty  attend- 
ing its  control.  The  beetle  itself  is  less  than  one-fourth  of  an 
inch  in  length,  chunky  in  appearance,  brown,  with  black  and 
gray  mottlings,  and  with  four  elevated  excrescences  on  the  wing- 
covers.  The  beetle  hibernates  and  appears  in  early  spring,  feed- 
ing first  upon  the  unopened  buds  and  afterward  upon  the  young 


THE    INSECT   WORLD. 


233 


Fig.  240. 


Plum-curculio,  Conotrachelits  iinnt- 
phar. — a,  larva  ;  b,  pupa  ;  r,  adult  ;  (/, 
beetle  at  work  on  a  young  ])lum,  show- 
ing a  crescent  mark. 


leaves  of  plum,  peach,  apricot,  cherry,  apple,  and  pear.  When 
the  fruit  has  set  and  become  of  the  size  of  a  marble,  the  insect 
makes  a  crescent-shaped  slit,  elevating  a  small  flaj)  from  the  sur- 
rounding tissue,  and  in  this  it  lays  an  Q^<g.  The  latter  hatches 
in  a  few  days,  and  the  whitish,  grub-like  larva  bores  at  once  to 
the  seed  capsule,  causing  the 
fruit  to  fall  from  the  tree  and  rot 
in  the  plum,  peach,  apricot,  and 
cherry,  though,  except  in  tlie 
plum,  this  dropping  is  not  uni- 
versal. Apples  and  pears  do  not 
drop  as  a  result  of  curculio  in- 
jury, and,  except  in  a  few  varie- 
ties of  ai)ples,  the  larva  is  unable 
to  mature  in  the  fruit  remaining 
on  the  tree.  In  apples  and  pears 
that  drop  from  other  causes,  the 
larva  develops  freely.  By  mid- 
summer, growth  is  complete,  the 
larvae  leave  the  now  decayed 
fruits  and  go  underground  to  pupate,  changing  to  the  adult,  or 
beetle,  form  a  short  time  thereafter.  These  go  into  hiding  almost 
immediately,  and  are  not  again  seen  until  the  spring  following. 
Remedial  measures  in  this  case  have  not  proved  entirely  satisfac- 
tory. The  larva  is  beyond  reach  of  all  insecticides,  and  can  be 
destroyed  only  by  persistent  and  thorough  gathering  of  all  fallen 
fruit  at  intervals  of  a  few  days  throughout  the  early  part  of  the 
summer.  Chickens,  turkeys,  hogs,  or  sheep  accomplish  the  .same 
purpose  less  completely  and  lessen  if  they  do  not  prevent  injury. 
The  beetles  may  be  reached  by  spraying  the  trees  before  the  buds 
open  with  one  of  the  arsenites,  destroying  them  before  they  have 
a  chance  to  oviposit.  Spraying  may  be  continued  after  the  fruit 
has  set,  to  kill  the  beetle  while  eating  out  its  crescents.  Some 
part  of  the  fruit  is  always  injured,  though  a  sufficiently  large 
percentage  to  pay  for  the  insecticide  application  is  usually  saved. 
Jarring  the  trees  every  day  or  two  over  a  sheet  or  other  recep- 
tacle has  been  practised  with  good  success,  as  the  beetles  drop 
readily  and  lie  quietly  for  some  time,  especially  early  in  the  day, 
allowing  themselves  to  be  easily  gathered  up   and   destroyed. 


234 


AN  ECONOMIC  ENTOMOLOGY. 


This  is  one  of  those  cases  where  persistent  and  universal  practice 
is  desirable  to  obtain  the  best  results. 

An  allied  but  larger  species  of  the  same  genus  without  the 
elevations  on  the  wing-covers  is  C.  crataegi,  which  attacks  the 
quince  and  sometimes  does  considerable  injifry,  much  as  the  C. 
nenuphar  does  on  the  fruits  above  enumerated.  The  same 
measures  are  indicated  here  also. 

The 'potato-stalk  borer,  Trichobaris  j-notata,  is  a  small  ash- 
gray  weevil  about  one-sixth  of  an  inch  in  length,  with  a  black 

Fig.  241. 


Potato-stalk  borer,  Trichobaris  trinoiata. — Larva,  pupa,  and  adult. 

snout  and  three  small  black  spots  at  the  base  of  the  wing-covers. 
It  lays  its  eggs  into  the  stems  and  larger  branches  of  the  potato, 
horse-nettle,  Jimpson-weed  {^Datura  stramonium),  and,  perhaps, 
other  Solanaceae,  and  the  white  larvae  feed  there  until  after  mid- 
summer, changing  to  pupae  at  about  the  time  when  the  potato- 
vines  mature,  and  to  adult  beetles  a  short  time  thereafter.  The 
beetles  remain  in  their  larval  burrows  during  the  winter,  and  may 
be  easily  destroyed  by  burning  the  vines  immediately  after  the 
potatoes  are  harvested. 

The  species  of  Balanmus  are  known  as  nut-weevils,  are  of 
quite  large  size,  clay-yellow  in  color,  and  with  an  exceedingly 
long  and  slender,  black  beak  or  snout.  By  means  of  this  they 
puncture  the  burrs  of  young  chestnuts,  the  husks  of  hickory  and 
walnuts,  and  the  green  coverings  of  young  acorns,  reaching  near 
the  centre  of  the  nut  itself,  and  placing  an  &^^  in  the  hole  so 


THE    IXSECT   WORLD. 


235 


made.     The  larva  hatches  and  the  little  wound  through  which 
the  ^%%  was  laid  heals  so  completely  that  no  trace  of  it  is  visible 

KiG.  242. 


Work  of  the  potato-stalk  \io\^x,Trichobaris  3-notata,  in  potato-vines. 


in  the  fully  developed  fruit.     When  the  nut  is  ripe  and  drops  to 
the  ground  the  larva  is  full  grown,  and  eats  a  round  hole  in  the 


236 


A  A'  ECONOMIC  EXTOMOLOGY. 


Chestnut-\vee\  il,     Balanimts    rectus.  —  a,    from 
above  ;  b,  in  outline,  from  side;  c,  lar\a. 


shell  through  which  it  makes  its  way  and  goes  underground  to 
pupate.     Thus  it  winters,  and  the  beetles  emerge  in  spring  when 

the  nut-trees  are  in  bloom, 
'*^'  ^'^•^'  Considerable      injury      is 

sometimes  caused  in  cul- 
tivated chestnut  groves, 
and  the  onl}-  way  to  avoid 
it  is  to  gather  the  nuts 
systematically  as  soon  as 
they  fall,  and  either  ship 
them  at  once,  or  store 
them  in  tight  boxes  or 
barrels,  from  which  the 
larvae  cannot  escape  when 
they  come  out.  They  will  then  be  found  at  the  bottom  when 
the  nuts  are  removed,  and  may  be  easily  killed. 

In  many  localities  corn  is  attacked  soon  after  it  shows  above 
ground  by  insects  known  as  "  corn  bill-bugs."  These  belong  to 
the  genus  Sphenophonis,  and  are  black  or  brown,  rarely  gray  in 
color,  varying  from  one-fourth  to  half  an  inch  in  length,,  with 
very  thick  and  hard  wing-covers,  which  are  ridged  and  punc- 
tui-ed,  as  is  also  the  thorax.  They  hide  during  the  day  in  the 
soil  at  the  base  of  the  corn-plants,  and  kill  them  by  boring 
little  round  holes  in  the  stem.  They  are  most  frequent  after 
timothy,  especially  on  old  sod,  or  when  corn  follows  sedges  or 
bulb-rooted  grasses.  It  is  in  such  places  that  the  larvae  live 
naturally,  pupating  in  fall  or  early  spring,  and  the  beetles,  finding 
on  spring  ploughed  land  that  their  natural  food  is  gone,  attack  the 
corn,  which  replaces  and  is  nearly  enough  like  it  to  be  to  their 
taste.  The  period  of  injury  is  usually  short,  and  by  delaying 
replanting  a  little,  the  new  shoots  escape  attack.  Fall  ploughing 
old  timothy  sod  or  sedge-land  is  always  indicated,  and  will  gen- 
erally serve  to  reduce,  if  it  does  not  entirely  prevent,  injury. 

To  this  same  series  belongs  the  largest  of  our  weevils,  the  Rhyn- 
chophoriis  palmarum,  or  "palm-weevil,"  which  often  exceeds  an 
inch  in  length  and  whose  fat,  white  larva,  boring  in  palm,  is  said 
to  be  quite  a  delicacy  to  the  taste  of  the  aborigines  of  Central 
and  South  America. 

Much  resembling  it  in  shape  but  hardly  exceeding  one-eighth 


THE    IXSECT    WORLD. 


237 


of  an  inch  in  length  arc  the  grain  weevils,  belonging  to  the  genus 
Calandra.  These  are  almost  cosmopolitan,  and  infest  stored 
grains  of  all  kinds.  They  are  black  or  brown-red  in  color,  quite 
slender,  and  on  a  very  small  scale  resemble  the  ' '  corn  bill-bugs' ' 
in  sculpture.  They  can  be  easily  controlled  by  the  use  of  bisul- 
phide of  carbon  poured  on  the  grain  in  bins  or  other  receptacles, 

Fit;.  244. 


Splisiiopho)  us  ochrciis. — Adult,  larva,  and  work  in  roots  of  Scirpus. 

covering  with  canvas  or  similar  material  to  prevent  the  too 
rapid  escape  of  the  fumes  which  gradually  permeate  the  entire 
mass  of  grain,  killing  everything  in  it. 

Closing  the  series  we  have  the  bark-beetles,  or  Scolytids,  some 
of  them  called  shot-hole  borers  from  the  little  round  holes  with 
blackened  edges  which  they  make  in  wood  and  bark.  Many 
species  make  prettily-figured  burrows  between  the  bark  and  sap- 
wood,  while  others  bore  into  the  solid  wood,  making  longer  or 
shorter  galleries.  Mo.st  of  the  species  attack  forest-trees,  and  for 
them  reference  should  be  had  to  Dr.  Packard's  work  already  cited. 


238 


^jV  economic  entomology. 


These  beetles  dififer  from  all  the  other  weevils  in  their  cylin- 
drical form  and  very  short  snout,  which  is  scarcely  more  than  a 
slight  prolongation  of  the  head,  and  they  are  usually  of  small 
size,  most  of  them  not  exceeding  one-eighth  of  an  inch  in  length. 

Fig.  245. 


Calandra  granaria. — a,  adult  ;  b,  larva  ;  c,  pupa  ;  d,  C.  oryza,  adult. 

Scolytiis  riigulosiis,  the  "fruit-bark  beetle,"  is,  perhaps,  the 
best  known,  and  certainly  the  most  important  economically, 
attacking  deciduous  fruit-trees  of  almost  all  kinds.  The  black 
parent  beetles  appear  in  early  spring,  and  bore  little  round  holes 
through  the  bark  to  the  sap-wood.  They  then  make  a  central 
burrow,  on  each  side  of  which  little  notches  are  made  to  receive 
the  soft  white  eggs.  The  larvae  hatch  very  soon,  and  at  once 
begin  to  make  little  burrows  of  their  own,  diverging  as  they 
move  from  the  parent  channel,  and  gradually  enlarging  them  as 
they  increase  in  size.  When  full  grown  they  form  a  slightly 
enlarged  chamber,  in  which  they  pupate,  and  when  they  trans- 
form to  beetles,  make  their  way  out  through  little  round  holes 
in  the  bark.  The  whole  period  of  development  does  not  exceed 
a  month,  and  there  may  be  several  broods  during  the  summer 
from  the  same  tree,  the  numerous  galleries  eventually  girdling 
and  killing  it. 


Mi     ■ 


>  ■■:a 


;  ill,*, ¥'''«'/; 


'  ( 


^'l 


fri4;i\ 


1^ 

1'. 

1 

J 

1  • 

i          ; 

■i-^    ^. 


'!  Ml! -A 


hi     ♦ 


A  piece  of  hickory  baik,  illuairatinjj;  tlic  w^rk  ot  ^ci//>^.o  ^-o/ii/n/o»o  unU  .u  Ui.\. 
natural  size. 


THE    IXSECT    WORLD. 


239 


I""i(;.  246. 


Fruit-bark     beetle,      Scohtus 
iiigiilosiis,  mucli  enlarged. 


These  insects  rarely  attack  sound,  healthy  trees,  and  this  is  a 
peculiarity  of  bark-beetles  in  general,  though  there  are  many 
exceptions.  But  just  as  soon  as  a  tree  becomes  a  little  weakened 
through  injury  or  from  starvation,  these 
little  creatures  attack  it,  and  then  its 
doom  is  sealed,  unless  vigorous  meas- 
ures are  taken  at  once.  Peach-trees  are 
especially  susceptible  to  injury,  and  the 
gummy  oozings  from  the  little  holes 
seem  to  weaken  them  so  rapidly  that 
they  succumb  in  a  short  time. 

It  is  good  practice  to  keep  orchard 
trees  in  the  best  possible  health  and 
vigor  at  all  times  to  enable  them  to  resist 
naturally  the  attacks  of  these  insects, 
but  if  one  does  become  seriously  infested 
it  should  be  at  once  cut  out  and  burnt. 
It  is  certain  to  die  in  a  short  time,  and     . 

it  is  a  constant  menace  to  surrounding  trees  from  the  abundance 
of  specimens  which  will  be  produced,  ready  to  attack  others  at 
the  least  sign  of  weakness.  Where  a  slight  infestation  is  noticed 
on  a  tolerably  healthy  tree,  it  should  be  closely  examined  to 
ascertain  the  original  source  of  weakness,  and  when  this  is  re- 
moved the  tree  should  be  stimulated  by  means  of  appropriate 
fertilizers,  and  the  trunk  kept  covered  by  whitewash  to  which 
Paris  green  has  been  added.  Strong  whale-oil  soap-suds  will 
answer  the  same  purpose,  and  a  little  crude  carbolic  acid  will 
add  to  its  effectiveness.  In  all  cases  the  application  should  be 
thorough,  and  should  be  kept  intact  until  the  tree  has  fully 
recovered  and  is  able  to  take  care  of  itself 

The  same  line  of  treatment  is  adapted  to  other  bark-beetles, 
varied  according  to  the  differences  in  life  history. 

To  recapitulate  in  a  general  way,  beetles  and  their  larvae  are 
mandibulate  and  chew  their  food  ;  therefore,  whenever  they  feed 
openly  upon  plant  tissues,  they  may  be  killed  by  arsenical  sprays. 
Internal  feeders  must  be  dealt  with  as  indicated  by  their  life 
habits,  but  we  must  look  rather  to  preventive  than  to  remedial 
measures  in  such  cases. 


.140 


AiV  ECONOMIC  ENTOMOLOGY. 


CHAPTER    VII. 

THE    LEPIDOPTERA. 

Butterflies  and  Moths. 

Under  the  term  Lepidoptera  are  included  those  insects  popu- 
larly known  as  butterflies  and  moths,  in  which  the  wings  and 
body  are  more  or  less  clothed  with  scales.  These  scales  often 
differ  greatly  in  form  and  size  even  in  the  same  insect,  and  yet 
more  in  different  groups,  so  that  a  certain  family  or  series  may 
show  types  peculiar  to  it  alone.     Oddly  enough,  there  is  some- 


FlG 


Fig.  249. 


Scales  on  wing  of  butterfly. 


Head  of  a  moth.  —  The 
tongue  uncoiled  at  a;  seen 
from  side,  partly  coiled,  at 
b  ;  the  appearance  of  tongue 
under  a  lens  at  c. 


times  a  difference  even  in  the  sexes,  certain  kinds  of  highly 
developed  scales  occurring  on  the  wings  of  the  male  only, 
usually  confined  to  limited  areas  and  sometimes  concealed  by 
folds. 

In  this  order  the  adult  insects  are  harmless  throughout,  capable 
of  feeding  only  upon  liquid  food  by  means  of  a  tongue  which 
is  usually  coiled  like  a  watch-spring  on  the  under  side  of  the 
head  between  the  palpi.  In  some  instances  it  is  wanting,  and 
on  the  other  hand  sometimes  becomes  enormously  developed, 
reaching  a  length  in  some  species  of  from  five  to  nearly  seven 


THE    IXSECT   WORLD. 


241 


Fig.  250. 


inches.  Many  of  the  Lcpidoptera  are  useful  in  pollenizing 
flowers,  some,  indeed,  depending  entirely  upon  them  for  their 
continued  existence,  but,  on  the  other  hand,  the  caterpillars,  as 
the  larvie  are  usually  called,  are  among  the  most  troublesome 
and  injurious  insects  with  which  the  agriculturist  has  to  deal. 
The  transformation  in  this  order  is  comj^lete,  and  a  greater 
difference  than  that  between  caterpillar  and  butterfly  can  hardly 
be  imagined  ;  while  in  the  chrysalis  or  pupa  we  have  a  quiescent 
period  where  scarcely  even  the  form  of  the  future  insect  is  indi- 
cated, and  when  it  is  absolutely  incapable  of  motion. 

Broadly,  the  order  is  divided  into  butterflies  and  moths,  or, 
more  accurately,  the  Rhopalocera  and  Heterocera.  Rlwpalocera 
are  those  in  which  the  antennae,  or 
feelers,  terminate  in  a  more  or  less 
distinct  knob  or  club  at  the  tip,  and 
in  which  at  least  the  front  pair  of 
wings  are  elevated  or  vertical  when 
at  rest,  so  that  the  upper  surfaces 
touch.  The  Heterocera,  on  the 
other  hand,  have  feelers,  or  anten- 
nae, of  many  different  kinds,  but 
never  in  our  fauna  distinctly 
clubbed.  The  wings  when  the 
insect  is  at  rest  are  horizontal, 
folded  on  the  back  or  close  to  the 
sides,  oblique,  roof-like,  or  spread 
out  flat,  but  never  habitually  ver- 
tical. In  general  it  may  be  said 
that  the  butterflies  are  on  the 
wing  during  the  day,  and  fly  dur- 
ing the  night  only  in  rare  in- 
stances ;  moths,  on  the  other  hand, 
are  night  flyers,  as  a  rule,  though  there  are  many  exceptions, 
and  a  number  of  species  occur  commonly  during  the  day. 

The  butterflies  separate  readily  into  groups  based  on  the  char- 
acter of  the  feet  and  the  situation  of  the  antennae.  What  may 
be  called  for  convenience  the  "  true  butterflies  "  are  distinguished 
by  having  the  feelers  set  close  together  on  the  top  of  the  head, 
the  latter  being  proportionately  rather  narrow.     The  antennal 

16 


Antennae  in  Lepidoptera.  —  a, 
clubbed  antenna  of  butterfly  ;  b,  c, 
variations  in  form  of  club;  d,  prismatic 
and  fusiform  ;  e,  ciliated  ;  _/",  bristle- 
tufted  ;  g,  doubly  bipectinated. 


242 


AN  ECONOMIC  ENTOMOLOGY. 


club  is  abrupt  at  the  tip  and  not  drawn  out  into  a  hook  or 
recurved.  In  the  skippers,  or  Hesperids,  the  head  is  broad,  the 
eyes  are  comparatively  small,  the  feelers  are  widely  separated, 
set  close  to  the  eyes,  and  terminated  by  a  pointed  tip  which  is 
often  recurved  or  hooked. 

A  large  series  of  the  true  butterflies  is  distinguished  by  having 
the  anterior  pair  of  feet  more  or  less  aborted  or  imperfect,  and 
these,  the  "brush-footed  "  butterflies,  are  classed  in  two  famihes. 


Fig.  251. 


Fig.  252. 


yCC- 


Ir 

a,  head  of  Papilio,  show- 
ing where  anteiinse  are  in- 
serted ;  b,  same  of  an 
Hesperid. 


a,   foreleg  of  a  brush-footed    butterfly  entirely 
aborted  ;  b,  of  Lyctziia,  male,  tarsus  one-jointed. 


the  NymphalidcB,  containing  moderate-sized  or  large  species,  and 
the  Lyccenidis,  containing  small  species,  in  which  the  colors  are 
blue  or  coppery,  or  have  the  under  sides  marked  with  fine, 
thread-like  lines.  They  are  the  "blues,"  "coppers,"  and 
' '  hair-streaks. ' ' 

Among  our  most  common  species  of  the  first  family  is  the 
"milk-weed  butterfly,"  Danais  archippus,  quite  a  large  red- 
brown  insect,  with  the  wing-veins  broadly  black  marked.  It 
becomes  abundant  in  late  summer  and  fall,  and  its  caterpillar, 
green  in  color,  marked  with  black  lines,  and  furnished  with  rather 
long,  black,  hair-like  tentacles,  may  be  often  seen  feeding  upon 
milk-weeds.  This  species  will  serve  to  typify  the  family  to  which 
it  belongs,  and  is  easily  raised  by  any  one  curious  to  watch  its 
transformations.  If  the  caterpillar  be  confined  with  a  sufficient 
supply  of  fresh  leaves,  it  will  grow  to  about  an  inch  and  a  half  in 
length,  will  then  fasten  itself  by  means  of  its  hind  feet  to  a  little 
pad  of  silk,  and  will  change  to  a  chunky,  bright-green  chrysalis, 
or  pupa,  marked  with  small  golden  spots,  one  of  the  prettiest 
objects  that  can  be  imagined.     In  a  few  days  the  color  will  be- 


THE    INSECT   WOKLD. 


243 


come  darker,  finally  brown  or  blackish,  and  then  the  butterfly- 
will  emerge.     This  is  not  an  injurious  insect,  and  is  only  referred 

Fig.  253. 


Milk-weed  butterfly,  Danais  arcliippus,&nA  its  transformations. — A,  a,  egg  enlarged 
thirty  diameters  ;  b,  very  young  larva,  showing  how  the  tentacles  are  folded  ;  <:,  egg, 
natural  size,  on  a  leaf;  B,  full-grown  larva  ;   C,  chrysalis  ;  D,  male  butterfly. 

to  here  because  it  is  easily  raised  and  common   throughout  the 
country, — in  fact,  has  spread  all  over  the  globe. 


244  ''^^^-    ECONOMIC   ENTOMOLOGY. 

We  have  many  species  of  considerable  size  belonging  to  the 
genus  Argynnis,   which  resemble  each  other  more  or   less  by 

their    tawny    upper    sides 
Fic-..  254.  marked  with  black  spots, 

and  by  having  the  under 
sides  more  or  less  marked 
with  silvery  blotches,  es- 
pecially on  the  hind  wings. 
None  of  them  are  injurious, 
the  larvae  feeding  upon  vio- 
lets. In  the  genus  Grapta 
there  are  species  with 
C;a/./<j/.r<'.cr'"-.'^\viiiKsofTightsirie  detached     strougly    and     irregularly 

to    show    under   side;     this    is    almost     like  G.       angulatcd        and        tOOthed 
comma.  ■  ■  111 

wmgs,  quite  dark  brown 
in  color,  with  irregular  black  or  blackish  blotches,  spots,  and 
lines,  and  a  little  silvery  mark  resembling  a  comma  or  semicolon 
on  the  hind  wings  beneath.  Of  these  the  caterpillar  of  G.  comma 
feeds  upon  the  hop-vine,  although  it  rarely  does  any  serious 
injury.  It  is  reddish  or  yellowish  in  color,  with  a  black  head 
and  black  branched  spines,  and  forms  an  angular  chrysalis  which 
is  suspended  by  the  tail.  The  chrysalis  is  yellowish  green  in 
color,  with  prominently  marked  segments,  and  has  the  thorax 
produced  into  a  somewhat  acute  process. 

Another  very  common,  almost  cosmopolitan  butterfly,  is  the 
Vanessa  antiopa,  popularly  known  as  the  "mourning-cloak." 
It  is  of  a  very  dark,  rich-brown  color,  with  a  broad  yellowish 
border  on  both  wings.  It  winters  in  the  butterfly  stage,  and 
may  often  be  seen  on  warm  days  in  midwinter,  fluttering  about  in 
the  woods,  while  it  is  the  earliest  of  the  butterflies  to  make  its 
appearance  in  spring.  The  caterpillars  feed  upon  quite  a  variety 
of  plants,  notably  willow  and  poplar,  and  often  in  great  colonies. 
When  full  grown  they  are  two  inches  or  more  in  length  and  black, 
with  red-marked,  branched  spines.  The  chrysalis  is  suspended 
by  the  tail,  and  of  a  somewhat  mouse-gray  color,  the  segments 
marked  with  acute  spines.  This  may  under  circumstances  be- 
come a  troublesome  insect,  but  it  is  easily  controlled,  either  by 
arsenical  poisons,  as  the  caterpillar  feeds  exposed,  or  by  hand- 
picking,  which   is  easy  because  of  the  gregarious  habit  when 


THE    INSECT    WORLD. 


245 


younq;.  A  nuinber  of  other  common  species  belong  in  this 
family,  but,  as  they  do  not  feed  upon  cultivated  plants  in  suffi- 
cient numbers  to  attract  attention,  they  need  not  be  further 
considered. 

Fig.  256. 


Larva  and  chrysalis  of  I'aiirssa  antiopa. 

Quite  early  in  spring  we  may  see,  fluttering  along  the  road- 
sides, little  blue  butterflies  expanding  less  than  an  inch  when  the 
wings  are  spread,  and  without  prominent  markings  of  any  kind. 
These  belong  to  the  family  LyccenidcB,  usually  to  the  typical 
genus  LyccEua,  and  from  them  the  term  "blues,"  as  a  popular 
name,  has  been  derived.  Later  in  the  summer  we  find  com- 
monly bright  coppery  butterflies,  not  much  larger  than  the 
"  blues  "  already  spoken  of,  and  on  the  upper  surface,  especially 


Fig.  258. 


Chrys,o[>tiaiius  t/ior. — Male  and  female. 

of  the  fore-wings,  are  black  spots  varying  in  size  and  arrange- 
ment. To  these  the  name  "coppers"  has  been  applied,  and 
they  belong  to  the  natural  genus  Chrysopha)ius.  The  genus 
TJiecIa  contains  species  that  run  larger  than  either  of  those  pre- 
viously mentioned,  many  of  them  sombre  in  color  and  marked 
on  the  under  side  by  fine,  hair-like  streaks,  differing  in  arrange- 
ment and  not  always  present.     These  are  called  "hair-streaks." 


246  AN  ECONOMIC   ENTOMOLOGY. 

The  hind  wings  are  often  furnished  with  one  or  two  pairs  of 
slender,  thread-like  tails,  easily  broken  off  if  the  insects  are  care- 
lessly handled.  None  of  the  members  of  this  family  are  injurious, 
and  the  somewhat  slug-like  caterpillars  are  not  often  seen. 
Fenesica  tarquinius  looks  like  one  of  the  "  coppers,"  and  is  pe- 
culiar in  that  its  larva  feeds  on  the  woolly  plant-lice  often  found 
on  beech  and  other  trees.  It  is  the  only  butterfly  larva  in  our 
country  which  is  known  to  be  predaceous. 

The  family  PapilionidcE  contains  six-footed  butterflies,  the 
anterior  feet  being  perfectly  developed  in  both  sexes,  and  here 
the  antennae  are  set  rather  close  together  at  the  base.  It  includes 
our  largest  and  brightest  species,  the  most  prominent  of  them 
being  known  as  "swallow-tails,"  There  are  two  groups,  the 
first  containing  smaller  species,  which  are  white  or  yellow  in 
color,  the  hind  wings  without  tails,  but  furnished  with  a  fold 
along  the  inner  margin,  forming  a  groove,  in  which  the  abdomen 
lies.  These  are  arranged  under  the  term  Pierince,  and  contain 
as  typical  forms  the  common  cabbage  butterflies.  The  most 
abundant  and  injurious  of  these  is  Pieris  rupee,  an  insect  imported 
many  years  ago  from  Europe,  and  which  has  now  spread  over 
the  largest  part  of  the  United  States  and  Canada.  The  wings 
expand  about  an  inch  and  a  half,  are  white  or  with  a  creamy 
tinge,  with  a  single  black  spot  in  the  fore-wings  of  the  male,  and 
two  similar  spots  in  those  of  the  female.  There  is  also  a  little 
black  patch  at  the  apex,  and  on  the  under  side  the  wings  are 
usually  darker  and  a  little  powdery.  These  butterflies  appear 
very  early  in  spring,  emerging  from  chrysalids  that  have  hiber- 
nated, and  lay  their  eggs  upon  almost  any  of  the  cruciferous 
weeds.  They  are  not  particularly  choice,  but  perhaps  the  com- 
mon Barbarea  vulgaris  is  about  as  often  selected  as  any  in  the 
Middle  States,  because  one  of  the  first  to  make  its  appearance. 
The  first  brood  comes  to  maturity  in  less  than  a  month,  and  then 
eggs  are  laid  on  early  cabbage-plants.  Soon  irregular  holes 
appear,  first  in  the  outer  leaves,  then  in  the  head  itself,  and  little 
piles  of  dirty-yellow  excrement  may  now  be  found  everywhere 
among  the  folds.  The  caterpillars  themselves  are  velvety  green 
in  color,  almost  like  the  cabbage-leaf,  and,  as  they  lie  rather 
closely  to  the  plant  tissue,  are  easily  overlooked  until  a  little 
practice  is   gained  in  searching  for  them.     They  become  more 


I'^IG.    260. 


Fig.  265. 


Fig.  261. 


Fig.  264. 


Fig.  259. 


Fig.  262. 


Fig.  259,  Thecla  strigosa.  Fig.  260,  Pieris  rapes,  male.  Fig.  261,  Ptois  raptT,  female. 
Fig.  262,  a,  larva;  b,  chrysalis  of  Pieris  rapce.  Fig.  263,  Pieris  prolodice,  male.  Fig. 
264,  Pieris  prolodice ,  female.    Fig.  265,  larva  and  chrysalis  of  P.  prolodice. 

247 


248  AN  ECONOMIC  ENTOMOLOGY. 

abundant  as  the  season  advances,  and  late  cabbage  often  suffers 
seriously  in  some  localities.  By  all  odds  the  best  remedy  is 
spraying  with  the  arsenites,  at  the  rate  of  about  one  pound  in 
one  hundred  and  fifty  gallons  of  water.  A  great  many  other 
remedies  have  been  recommended,  and  some  of  them  are  un- 
doubtedly useful,  but  nothing  is  so  satisfactory  and  cheap  as  the 
arsenite,  and  without  gross  carelessness  there  is  not  the  slightest 
danger  in  the  application.  The  cabbage  heads  from  within, — 
that  is  to  say,  the  leaves  unfold  from  the  centre  of  the  head  and 
do  not  fold  together  to  form  it ;  therefore,  whatever  poison  is  put 
upon  the  plant  can  fall  only  upon  the  outer  leaves,  and  not  a 
particle  gets  into  the  head  itself  The  amount  used  to  a  single 
cabbage-plant  is  so  minute  that  in  order  really  to  poison  a  man  it 
would  be  necessary  for  him  to  eat  about  a  dozen  heads,  outer 
leaves  and  all,  and  if  death  then  resulted  I  would  be  inclined  to 
attribute  it  rather  to  the  cabbage  itself  than  to  the  Paris  green  or 
other  arsenite  employed.  The  larvae  succumb  to  the  poison  very 
readily,  and  by  making  the  application  early  in  the  season  the 
later  broods  may  be  materially  reduced  in  number.  In  ordinary 
farm  practice  the  heads  are  cut  out  and  shipped,  and  in  prepar- 
ing the  cabbage  for  food,  the  outer  leaves  of  these  heads  are 
generally  taken  off  by  the  housewife  because  more  or  less  bruised 
or  injured,  before  they  are  cooked.  Chemical  analysis  has  shown 
that  on  a  head  so  prepared,  within  a  week  after  a  heavy  applica- 
tion of  Paris  green,  not  a  trace  of  arsenic  remained.  As  a  matter 
of  fact,  the  use  of  Paris  green  as  against  the  insect  is  quite 
common,  although  little  is  said  of  it,  to  avoid  exciting  prejudice, 
and  I  have  yet  to  learn  of  the  first  case  of  arsenical  poisoning 
from  eating  cabbage  so  treated.  From  New  Jersey  southward 
and  westward,  one  of  our  native  species,  P.  protodice,  becomes 
more  common  and  assists  its  imported  relative  in  making  havoc 
among  the  cabbages,  but  this  also  may  be  easily  controlled  by  the 
measures  above  detailed. 

We  find  flying  abundantly  in  our  fields,  and  more  common 
among  clover,  a  bright,  sulphur-yellow  butterfly  about  as  large 
as  the  P.  rapes,  with  a  single  black  spot  on  the  fore-wings,  and  a 
broad  black  outer  margin  to  both  pairs.  On  the  under  side  the 
hind  wings  have  a  central  orange  spot,  often  with  a  slight  silvery 
tendency.     These  butterflies  belong  to  the  genus  Co/ias,  and  the 


rilE    INSECT   WORLD. 
Fig.   255. 


249 


Fig.  266. 


Fig.  257. 


Fig.  255,  mourning-cloak  butterfly,  Vanessa  antiopa.     Fig.  257,  Lyccena  pseudargiolus.     Fig.  266, 
Colias  philodice,  male.     Fig.  267,  same,  female.     F"ig.  272,  Nisoniades  juvenalis. 


250 


AN  ECONOMIC   ENTOMOLOGY. 


common  eastern  species,  extending-  westward  to  the  Rocky- 
Mountains,  is  C.  philodice^  whose  larva  feeds  upon  clover.  It  is 
a  green  caterpillar  somewhat  similar  to  the  "  cabbage- worm," 
but  although  it  may  be  quite  abundant,  rarely  does  injury  enough 
to  be  noticed.  As  a  rule,  the  larva  is  rather  difificult  to  find,  even 
where  the  butterflies  are  abundant,  and  practically  no  measures 
need  be  taken  against  it. 

In  the  sub-family  Papilionina;  we  have  in  our  country  only  the 
typical  genus  Papilio,  containing  species  abundant  enough  to 
become  of  economic  importance.     The  most  common  of  these  is 

Fig.  268. 


Papilio  asterias,  male. 

P.  asterias,  a  black  "  swallow-tail,"  expanding  between  two  and 
three  inches,  the  hind  wings  tailed  and  excavated  on  the  inner 
margin,  so  that  the  abdomen  is  free,  not  enfolded  in  a  groove. 
The  male  is  somewhat  smaller  than  the  female,  and  has  a  diag- 
onal row  of  yellow  spots  crossing  the  fore-wings  outwardly  and 
the  hind  wings  nearly  across  the  centre.  Near  the  outer  margin 
of  both  wings  there  is  a  row  of  yellow,  lunate  spots,  and  at  the 
inner  angle  of  the  hind  wings  is  a  peculiar,  eye-like  spot,  just  at 
the  margin.  The  female  has  the  inner  row  of  yellow  spots  very 
much  reduced,  sometimes  altogether  wanting,  but  on  the  hind 
wings  the  space  between  the  faint  series  of  yellow  spots  and  the 
outer  lunules  is  beautifully  powdered  with  metallic  blue  scales. 
These  butterflies  lay  their  eggs  on  carrots,  parsley,  and  other 
plants  of  the  same  natural  family,  and  from  them  hatch  bright 


THE    INSECT    WORLD. 


251 


green  caterpillars  with  broken  black  bands.  A  peculiarity  of 
tliis  kind  of  caterpillar  is  that  when  touched  or  irritated  in  any 
way  it  shoots  out  from  between  the  segments  close  to  the  head  a 
forked,  orange-colored  process,  which  emits  a  very  disagreeable 
odor,  and  this  is  its  only  means  of  defence.  No  trace  of  the  pro- 
cess is  visible  when  the  insect  is  at  rest,  and  the  horns  are  with- 
drawn just  as  soon  as  irritation  ceases.  When  the  caterpillar  is 
full  grown  it  leaves  the  plants  upon  which  it  has  fed  and  travels 
to  any  convenient  point  in  the  vicinity  where  it  can  pupate.  This 
pupa,  or  chrysalis,  is  fastened  to  a  little  silken  pad  by  the  tail, 

Fig.  269. 


Papilio  aslerias .—'W\iX\xx^  larva  and  pupa. 


but  is  also  sustained  by  a  silken  band  in  front  of  the  middle,  so 
that  it  is  said  to  be  girthed,  and  this  same  type  we  have  in  all  the 
members  of  this  family.  These  caterpillars  are  rarely  abundant 
enough  to  become  troublesome,  but  if  they  are,  hand-picking  is, 
perhaps,  as  good  a  remedy  as  any.  They  are  quite  prominent, 
and,  therefore,  easily  and  rapidly  gathered,  checking  their  injury 
immediately  and  completely.  When  they  are  small,  spraying 
with  the  arsenites  will  answer,  provided  it  be  done  thoroughly. 

Another  species  is  P.  phile^wr,  of  about  the  same  size,  black, 
without  the  yellow  spots  through  the  centre,  but  with  the  upper 
surface  overlaid  with  greenish,  powdery  scales,  which  give  the 
insect  a  metallic  lustre  in  certain  lights,  and  this  varies  according 
to  the  angle  at  which  the  light  strikes  the  wings.  The  cater- 
pillars feed  upon  vines  of  Aristoloc/ua,  or  "  Dutchman's  pipe," 
which  they  sometimes  injure  considerably.  They  are  dull 
brownish  red  in  color,  with  long,  fleshy  filaments  on  the  seg- 
ments, and  when    irritated  also   extrude   fleshy  horns   such   as 


252 


AN  ECONOMIC  ENTOMOLOGY. 


already  described  and  for  the  same  purpose.  The  measures 
recommended  for  the  parsley  caterpillar  may  also  be  adopted 
against  this  insect. 


The  largest  of  the  common  northern  "swallow-tail"  butterflies 
is  the  P.  turmis,  which  expands  from  three  to  six  inches,  and  is 


THE    INSECT    WOKI.D. 


253 


bright  yellow  in  color,  with  transverse  black  bands.  Towards 
the  South  and  West,  occurring  rarely,  however,  as  far  north  as 
Canada,  wc  have  a  form  of  the  female  which  is  black,  but  maybe 
distinguished  by  its  large  size  from  our  normally  black  species. 
The  caterpillar  is  green,  and  distinguished  by  having  two  black, 
eye-like  spots  on  the  anterior  segments.  It  feeds  on  a  number 
of  different  plants,  but  does  not  become  economically  imj^ortant. 
In  P'lorida,  P.  cresphontcs  is  abundant,  and  its  caterpillar  is 
known  as  the  "orange  dog,"  from  its  peculiar  appearance  and 

Fig.  271. 


The  orange  dog,  caterpillar  of  Papilio  cresphontes,  with  osmateria,  or  scent-organs, 
extended  ;  the  detached  figure  shows  the  anterior  segments  normally   retracted. 

habit  of  feeding  upon  orange-leaves.  The  butterfly  is  even  larger 
than  the  hirnus,  and  is  black,  with  a  broad  diagonal  band  of 
contiguous  yellow  spots  extending  from  the  tip  of  the  fore-wings 
towards  the  base,  reaching  the  inner  margin  very  near  to  the  base 
of  the  hind  wings.  There  is  also  a  band  of  yellow  spots  near  the 
outer  margin,  which  are  especially  prominent  on  the  hind  wings, 
and  a  yellow  spot  occupies  the  centre  of  the  broad,  lobed  tail. 
The  caterpillars  are  prominent,  as  already  stated,  and  orange- 
growers  consider  them  among  the  greatest  troubles  of  the  young 
trees,  especially  in  the  nurseries,  where  a  single  sj^ecimen  may 
defoliate  a  shoot  in  a  little  time.  Hand-picking  on  small  trees  is 
a  feasible  and  satisfactory  remedy,  and  another  is  to  capture  the 


254 


AN   ECONOMIC   ENTOMOLOGY. 


butterflies  on  the  flowers  which  they  frequent  during  the  middle 
of  the  day.  Mr.  Hubbard  has  suggested  shooting  them  with 
cartridges  loaded  with  sand,  and  that  can  easily  be  done  during 
mid-day  from  a  veranda  or  other  shelter  when  the  butterflies 
hover  around  the  flowers  near  by. 

The  "skippers,"  or  Hesperidcc,  differ  from  all  the  preceding 
by  the  broad  head,  clothed  with  bristly  hair,  and  by  the  widely 
separated  antennae,  or  feelers,  the  club  being  also  terminated  by 
a  more  or  less  marked  and  recurved  slender  booklet.  They  are 
small  or  moderate  in  size,  and  get  the  common  name  from  their 
jerky  habits  of  flight,  usually  along  roads,  and  practically  con- 
fined to  low  herbage.  There  are  two  rather  well-marked,  though 
by  no  means  sharply  limited  sections,  distinguished  by  color,  the 
first  containing  dark,  blackish  or  sombre  brown  types,  and  the 

other  tawny  yellow  forms. 
Fig.  273.  The  former  is  represented 

by  the  species  of  Nison- 
iades  and  its  immediate 
allies,  and  the  latter  by 
the  genus  Pamphila  and 
allies.  In  this  latter  se- 
ries the  fore-wings  are 
much  more  pointed  than 
in  the  other,  and  the  body 
is  proportionately  more 
robust.  None  of  the  species,  so  far  as  I  am  aware,  are  of  eco- 
nomic importance,  though  our  largest  species,  Megathymus 
yuccce,  does  some  injury  by  occasionally  boring  into  the  roots  of 
the  yucca  plant.  These  insects  have  been  considered  intermedi- 
ate between  the  butterflies  and  moths,  and  many  species  have 
the  habit  of  elevating  the  front  wings  only,  the  hind  wings  being 
held  horizontally. 

The  first  of  the  Heterocei-a  to  be  considered  here  are  the 
Sphingid(S,  or  ' '  hawk-moths, ' '  and  these  obtain  the  common 
name  from  their  habit  of  hovering  about  flowers,  and  their  rapid, 
darting  motions.  Most  of  them  fly  just  about  dusk,  visiting 
deep  flowers  like  the  "evening  primrose,"  "petunia,"  or  even 
"  Jimson  weed,"  and  they  succeed  in  reaching  the  very  bottom 
of  these  by  means  of  an  unusually  well-developed  tongue.     They 


Pamphila  ethliiis. 


THE    INSECT   WORLD.  255 

gather  their  iuod  while  hovering,  inserting  the  i)roboscis  into  the 


nectaries,  but  rarely  alighting.     The  antennae  are  prismatic  and 


256  ^A'    ECONOMIC   ENTOMOLOGY. 

spindle-shaped,  and  terminate  in  a  little,  recurved  hook.  The 
body  is  robust  and  well  developed,  supported  in  flight  by  means 
of  stout,  though  rather  narrow,  pointed  wings.  The  caterpillars 
are  peculiar  in  having  a  curved  horn  on  top  of  the  last  segment, 
or  in  its  place  a  hard,  glossy,  eye-like  spot.  When  at  rest,  some 
of  them  have  the  habit  of  elevating  the  front  part  of  the  body 
and  curling  the  head  under  a  little,  giving  them  a  fancied  resem- 
blance to  a  Sphinx,  and  from  this  the  scientific  name  has  been 
derived.  A  very  good  example  of  a  typical  sphinx  caterpillar  is 
found  in  the  large  green  species,  the  sides  with  oblique,  lateral, 
white  stripes,  which  is  often  found  upon  potatoes  and  tomatoes, 
occasionally  doing  considerable  injury.  The  anal  horn  is  quite 
often  believed  to  be  venomous,  and  all  sorts  of  stories  are  told  of 
people  having  been  poisoned  or  stung  ;  it  is  even  said  sometimes 
that  a  stream  of  poison  is  thrown  from  the  end  of  the  horn  for 
some  distance.  As  a  matter  of  fact,  nothing  can  be  more  harm- 
less than  these  caterpillars  ;  there  is  no  poisonous  secretion 
connected  with  the  horn,  and  they  can  be  handled  with  absolute 
safety.  This  same  type  of  caterpillar  also  attacks  tobacco  and 
other  Solanacece,  and,  when  full  grown,  goes  underground  and 
changes  to  a  mahogany-brown  pupa  an  inch  and  a  half  to  two 
inches  in  length,  wuth  a  peculiar  handle-like  process  attached  to 
the  head,  which  forms  a  covering  for  the  future  tongue.  This 
has  given  them  the  name  "jug-handle  grubs"  in  some  localities. 
The  adults,  when  they  emerge,  expand  from  three  to  five  inches 
or  more,  and  are  ashen-gray  in  color,  the  fore-wings  with  a 
little  white  spot  near  the  centre,  and  crossed  by  irregular  darker 
lines,  the  hind  wings  banded  with  black  and  white,  while  along 
the  sides  of  the  abdomen  are  five  large  yellow  spots.  This  is  the 
Sphinx  {Protoparce)  caroliiia,  which  may  be  accepted  as  typical 
of  the  series  to  which  it  belongs.  An  allied  species,  Protoparce 
ccleus,  feeds  on  the  same  kinds  of  plants,  and  resembles  the 
Carolina  rather  closely,  except  that  the  yellow  of  the  abdomen 
is  paler,  the  lines  on  both  wings  are  rather  more  distinct,  and 
the  insect  is  a  little  larger  ;  but  the  differences  are  not  great,  and 
need  not  be  further  detailed  here.  Other  species  of  sphinx 
caterpillars  are  found  on  a  variety  of  other  plants,  but  they  do 
not  often  appear  in  noticeable  numbers,  being  much  subject,  from 
their  large  size,  to  the  attacks  of  birds  and  parasitic  insects  ;  so, 


THE    INSECT    WORLD.  257 

« 

except  for  tlic  species  already  mentioned,  nature  herself  keeps 
down  the  insects  to  a  reasonable  number. 

Another  series  of  this  same  family  is  more  brightly  colored, 
with  the  wings  angulate,  dentate,  or  only  a  little  sinuate  at  the 
outer  margin,  and  of  these  we  have  several  species  that  attack 
the  vine.  The  caterpillars  are  rather  more  clumsy  than  those  of 
the  preceding  series,  and  the  head  is  often  retracted  into  the 
enlarged  thoracic  segments.  The  horn  is  frequently  wanting  and 
replaced  by  a  shining,  usually  blackish,  eye-spot.  These  are 
known  as  "hog-caterpillars,"  and  often  appear  in  numbers 
sufficient  to  cause  more  or  less  injury  in  vineyards.  The  adults 
are  brightly  colored,  either  greenish  with  darker,  blotchy  mark- 
ings, or  reddish  with  brown  markings,  or  a  combination  of  olive 
green  and  rusty  brown  and  gray.  The  figures  herewith  given 
illustrate  the  more  common  species,  and  as  their  habits  are  much 
the  same,  no  special  description  of  each  is  needed. 

On  the  elm-tree  we  sometimes  find  a  green  caterpillar,  the  skin 
a  little  roughened,  with  the  typical  sphinx  anal  horn  and,  in  addi- 
tion, four  little  horns  on  the  anterior  segments.  This  is  the  larva 
of  Ceratomia  amyjitor,  or,  as  Dr.  Harris  called  it,  much  more 
appropriately,  qiiadricornis,  which  means  four-horned.  The 
moths  produced  by  this  caterpillar  may  often  be  found  in  mid- 
summer on  the  trunks,  and  are  dirty  yellowish  gray,  streaked 
with  blackish,  and  with  white  discal  spots. 

Sometimes  we  find,  flying  around  flowers  in  bright  sunlight, 
exceedingly  active  little  creatures  that  at  first  sight  resemble 
humming-birds,  and  are  frequently  considered  such.  If  they  be 
captured,  however,  we  see  that  they  are  brilliantly  colored  moths, 
which  have  received  the  common  name  "humming-bird  hawk- 
moths.  ' '  They  usually  have  the  fore-wings  quite  sparsely  clothed, 
sometimes  nearly  transparent,  while  the  body  is  covered  by  rich 
coppery  or  other  metallic-colored  scales. 

The  caterpillars  in  this  family  are  all  external  feeders,  and 
usually  so  large  and  prominent  that  they  can  easily  be  seen.  In 
most  cases,  therefore,  the  simplest  remedy  is  hand-picking,  but 
when  this  is  done  no  caterpillar  should  be  destroyed  which  is 
covered  with  little,  white,  egg-like  bodies,  for  these  are  the 
cocoons  of  parasites  which  do  much  to  keep  the  insects  in  check. 
Where  the  larvae  are  abundant  enough  to  make  hand-picking 

17 


258 


AN  ECONOMIC  ENTOMOLOGY. 
Fig.   275. 


Fig.  275,  Philampeliis  paiidorus.    Fig.  276,  Philampeltis  acliemou,  larva.     Fig.  277, 
Philampelus  achemon. 


Fk;.  27S. 


Fig.  2S0. 


Fig.  27b,  Melittia  ci-to.  ilu-  Mniasli-liuixr  :  a,  b,  moth,  the  wings  sjjread  and  at  rest; 
c,  young  larvse  ;  d,  cocoon  with  the  enii)ty  pupa  shell  projecting.  Kig.  279,  squash- 
borers,  full  grown,  in  a  section  of  si|uash-\ine.  I-"ig.  j.So,  imported  currant-borer,  Sfsia 
lipuliforiiiis :  larva,  adult,  and  pupa  skin  projecting  from  the  cane. 


THE    INSECT   WORLD.  259 

impracticable,  any  of  the  arsenite.s  may  be  employed.  The 
attempt  has  been  made,  not  without  a  fair  degree  of  success,  to 
protect  tobacco  plants  by  killing  off  the  moths  while  feeding  in 
the  flowers  of  the  "  Jimson  weed,"  a  few  drops  of  a  poisonous 
solution  being  placed  in  the  bottom  of  each  flower.  It  is  perhaps 
questionable  whether  the  results  obtained  justify  the  method 
from  a  practical  stand-point,  and  the  direct  application  of  poison 
to  kill  the  larvie  is,  all  things  considered,  the  most  satisfactory. 

Following  the  hawk-moths  in  our  lists,  but  not  in  the  least 
related  to  them  structurally,  are  the  clear-winged  moths  belong- 
ing to  the  fuiiily  Scsiidcc.  They  are  slender  bodied,  with  quite 
long  antenuce,  the  wings  narrow,  often  without  scales,  the  colors 
metallic  or  at  least  glistening,  and  usually  bright  and  contrasting. 
They  often  resemble  and  are  considered  wasps  or  hornets  from 
their  appearance,  the  more  so  because  it  is  quite  usual  for  them 
to  have  the  abdomen  banded  with  yellow.  These  creatures  are 
the  parents  of  borers  that  are  among  the  most  injurious  to  culti- 
vated plants. 

First  in  the  series  is  the  "  squash-borer,  Jlfeliftia  cdo.  This  is 
readily  recognized  in  the  adult  stage  by  the  opaque,  greenish 
fore-wings,  and  by  the  unusually  large,  thickened  hind  legs, 
tufted  with  black  and  orange,  giving  the  insect  a  characteristic 
appearance,  different  from  any  other  common  species.  It  may 
be  found  during  late  spring  or  early  summer  hovering  about  the 
squash  or  other  cucurbit  plants  during  the  day,  but  in  the  even- 
ing and  during  the  night  resting  exposed  upon  the  leaves.  It 
lays  its  eggs  preferably  on  the  vine  just  at  the  surface  of  the 
ground,  if  the  soil  is  light  even  a  little  below,  but  it  is  by  no 
means  confined  to  this  point,  and  may  lay  them  anywhere,  even 
on  a  leaf  or  leaf-stalk.  They  are  brown  in  color,  disk-like,  and 
have  a  very  brittle  shell.  The  larvae  when  hatched  are  white  or 
nearly  so,  with  a  small  brown  head,  a  full  complement  of  legs, 
and  at  once  bore  into  the  stem  of  the  vine.  Preferably  they  live 
just  at  the  surface  of  the  ground,  really  eating  very  little  of  the 
plant,  but  rather  they  suck  the  juices,  causing  its  enfeeblement 
and  ultimate  death.  When  full  grown  in  midsummer  the  larva 
goes  a  short  distance  underground  and  forms  a  very  tough, 
parchment-like  cocoon  in  which  it  rests  until  the  year  following. 
In  spring  the  pupa,  by  means  of  its  chisel-like  head-case,  cuts  a 


26o 


AN   ECONOMIC  ENTOMOLOGY. 


circular  lid  from  the  cocoon,  wriggles  its  way  to  the  surface,  and 
through  it  into  the  open  air.  This  has  long  been  a  pest  to 
squash- growers,  and  the  usual  remedy  is  cutting  them  out  when 
the  wilting  vines  denote  their  presence.  This  is  quite  practical, 
but  has  the  disadvantage  of  being  very  slow,  besides  having  a 
tendency  to  injure  the  vines  if  the  cutting  is  unskilfully  done. 
Care  must  be  taken  to  cut  only  longitudinally,  while  the  wounds 
should  be  rubbed  with  dry  soil  and  covered  with  earth  to  facilitate 
healing.  Covering  the  joints  to  induce  rooting  is  advantageous, 
because  it  gives  new  sources  of  supply  for  plant  food  ;  so  that  even 
if  the  vine  be  entirely  severed  at  the  original  root,  it  may  mature 
fruit  from  the  suckers.  Where  squashes  are  raised  on  a  large 
scale,  the  best  method  is  to  trap  the  insects  by  a  first  crop  of 
some  summer  variety,  preferably  crook-necks.  These  grow 
rapidly,  and  the  moths  readily  lay  their  eggs  upon  them,  the 
plants  continuing  to  do  well  even  when  infested  by  the  larvse, 
and  maturing  an  early  crop  of  fruit.  The  late  squashes,  Hub- 
bard or  marrowfat,  may  be  planted  when  the  summer  varieties 
are  well  under  way,  and  by  the  time  they  are  large  enough  to 
be  attractive  to  the  moths,  most  if  not  all  the  eggs  will  have 
been  laid,  and  they  will  be  practically  exempt.  As  soon  as  the 
late  varieties  need  the  ground  the  sum- 
mer variety  should  be  carefully  removed, 
the  plants  being  taken  out  entire  and 
destroyed,  and  with  them  the  brood  of 
contained  larvae.  In  other  words,  the 
summer  squashes  are  to  be  used  as  a 
trap  crop  to  protect  the  Hubbard,  mar- 
rowfat, or  other  main,  late  variety.  It 
should  be  said  that  in  the  Central  and 
Southern  States  there  are  two  broods 
of  these  insects,  and  even  on  Long 
Island,  New  York,  a  few  specimens  are 
occasionally  found  in  September.  Vigor- 
ous war  on  the  first  brood,  however,  by 
means  of  traps  will  prevent  injury  from 
the  second. 

Blackberries  are  often  attacked  by  a  similar  larva  at  the  surface 
of  the  ground  or  a  little  below  it,  boring  sometimes  a  little  dis- 


Benibecia    marginata. 
male  ;  b,  female. 


THE    INSECT   WORLD. 


26] 


Fig 


tance  up  or  down  the  cane  or  completely  around  it,  for  which 
reason  it  has  been  called  the  "blackberry  crown-borer."  Signs 
of  its  presence  are  the  sudden  wilting  and  rapid  death  of  new- 
shoots,  and  it  comes  to  maturity  in  early  September  of  the 
second  year  of  its  life,  forming  a  pupa  in  the  stalk  itself  The 
resulting  moth,  Bcmbecia  viarginata,  is  black,  very  little  marked 
with  yellow,  and  the  only  satisfactory  remedy  is  cutting  out  and 
destroying  the  larva  as  soon  as  its  presence  is  indicated  by  the 
wilting  leaves. 

Perhaps  the  best  known  of  all  belonging  to  this  series  is  the 
"peach-borer,"  Sannina  cxitiosa.  This  is  the  pest  of  peach- 
growers  all  over  the  country,  and  the  larvae  live  between  bark  and 
wood  a  little  below  the 
surface  of  the  ground  in 
a  mass  of  gum  and  woody 
material.  They  first 
make  their  appearance 
after  midsummer,  and 
become  about  three- 
fourths  of  an  inch  long 
before  winter  sets  in.  In 
spring  they  resume  feed- 
ing, attaining  a  length  of 
a  little  more  than  an  inch, 
then  spin  a  cocoon  of 
silk  and  bits  of  chips 
covered  with  gum,  and 
change  to  a  pupa.  In 
this  stage  they  remain  a 
few  days  and  then  emerge 
as  moths.  The  sexes  are 
very  unlike,  the  males 
black,  with  narrowly  yel- 
low-banded abdomen, 
and  entirely  transparent  wings  ;  the  females  much  larger,  the 
fore-wings  almost  blackish  brown  and  entirely  covered  with  scales, 
the  abdomen  black,  with  a  broad  orange  band  at  about  the 
middle.  The  eggs  are  laid  on  the  bark  near  the  surface  of  the 
ground,  and  the  larvae  hatch  after  midsummer  in  time  to  do  con- 


The  peach-borer,  Satuiuia  exitiusa :    male 
female  below  ;  both  enlarged. 


above, 


262  AN  ECONOMIC  ENTOMOLOGY. 

siderable  feeding  before  winter  arrives.  "Worming"  peach- 
trees,  or  cutting  out  the  larvae,  is  a  recognized  method  of  getting 
rid  of  these  insects,  and  has  the  advantage  of  being  effective,  if 
thoroughly  done.  It  has  the  disadvantage  of  gashing  the  trees, 
and  sometimes  causing  a  considerable  amount  of  injury  before 
the  insect  is  found.  If  carelessly  done  a  few  will  escape,  and 
sooner  or  later  the  tree  becomes  girdled  at  the  base,  or  so 
weakened  that  it  proves  attractive  to  bark-beetles,  who  complete 
the  work  begun  by  the  borers.  Our  task  is  to  keep  the  insects 
out  if  possible,  and  the  best  method  is  to  cover  the  bark  with 
some  material  upon  which  the  insect  cannot  lay  its  eggs  or  through 
which  the  young  larvae  cannot  penetrate.  On  old  trees  white- 
lead  paint  in  boiled  linseed  oil  is  about  as  good  as  anything,  but 
it  should  not  be  used  on  young  trees,  nor  should  turpentine  be 
used  to  thin  out  the  lead  in  any  case.  On  younger  trees  white- 
wash thoroughly  applied  and  kept  on  from  quite  early  in  the 
spring  until  after  midsummer  will  answer  the  same  purpose,  but 
as  this  washes  off  readily,  it  must  be  renewed  as  often  as  the 
coating  becomes  imperfect.  Quite  a  satisfactory  method  is  to 
wrap  newspapers  or  tarred  paper  around  the  lower  two  feet  of 
the  trunk,  hilling  up  against  it  at  the  base  and  tying  at  the  top. 
This  must  be  replaced  yearly,  but  is  an  effective  protection  when 
well  put  on.  Fine  wire  netting  will  answer  the  same  purpose, 
and  has  the  advantage  of  being  more  lasting  ;  or  an  application 
of  cement  mixed  with  skim-milk,  applied  early  in  the  season 
and  maintained  until  midsummer,  will  serve.  Anything,  in  fact, 
that  forms  a  mechanical  protection  to  the  tree  will  answer, 
and  this  is  the  most  satisfactory  method  of  keeping  out  borers 
generally. 

There  are  other  species  of  this  family  boring  in  maple,  and 
their  empty  pupa  shells  may  often  be  seen  sticking  out  of  the 
bark  ;  and  so  plum,  pear,  and  a  great  variety  of  other  trees  are 
sometimes  attacked.  Where  maples  are  to  be  protected,  the 
whitewash  affords  the  best  hope  of  success,  unless  wire  netting 
much  finer  than  the  ordinary  mosquito  screening  is  employed. 
Sesia  acerni,  the  "maple  clear- wing,"  is  a  slender-bodied  little 
creature,  prettily  marked  with  red  and  yellow,  and  would  be 
able  to  oviposit  through  the  meshes  of  an  ordinary  mosquito 
screen  without  trouble. 


THE    INSECT    WORLD. 


263 


Currants  and  lilacs  arc  frequently  attacked  by  borers  of  this 
family,  and  on  currants  considerable  injury  is  sometimes  done  by 
Sesia  tipuliformis.  Here  the  best  remedy  is  to  cut  out  the  dead 
stalks  in  spring,  just  as  soon  as  leafing  out  shows  where  the 
attack  is  located,  and  every  wilted  shoot  seen  at  any  time  should 
be  cut  off  at  once  below  the  point  affected.  The  cut  stems  must, 
of  course,  be  burnt  inmiediately.  An  occasional  liberal  pruning 
back  will  prove  useful  in  keeping  down  the  insects,  and  is  some 
times  a  benefit  to  the  plants  as  well. 

As  a  whole,  we  may  say  that  our  methods  of  treatment  of  this 
family  are  in  the  nature  of  prevention  where  the  species  attack 
trees,  and  cutting  out  where  they  attack  shrubs  or  herbaceous 
plants. 

Grape-vines,  especially  in  city  gardens  or  in  villages,  are  often 
attacked  by  light-brownish  caterpillars  with  black  dottings, 
which  are  sometimes  so  abundant  as  actually  to  defoliate  them. 
They  become    nearly   an    inch 

and  a  half  in  length  when  full  ^'^-  ^^3. 

grown,  then  bore  into  any  soft, 
rotten,  or  e\'en  comparatively 
sound  wood,  where  they  pupate 
and  eventually  emerge  as  active 
httle  moths,  expanding  rather 
more  than  an  inch,  with  black 
fore-wings  having  two  pale  yel- 
low blotches,  and  black  hind 
wings  with  two  white  spots,  of 
which  that  near  the  base  is 
much  the  largest.  The  shoul- 
der tippets  are  yellow,  and  the 
insect  is  active  during  mid-day, 
hovering  about  the  vines  in  the 
brightest  sunshine.  It  is  the  Alypia  odo-maadata,  or  8-spotted 
forester,  common  throughout  the  Eastern  and  Central  United 
States  on  wild  as  well  as  cultivated  vines  and  Virginia  creeper,  but 
rarely  troublesome,  except  near  or  in  cities  or  towns.  The  cater- 
pillars feed  quite  exposed,  and  may  be  easily  destroyed  by  means 
of  the  arsenites.  In  city  gardens,  pyrethrum  in  the  form  of  a 
spray,  two  ounces  to  a  gallon  of  water,  will  prove  sufficiently 


Alypia  octo-ynacidata,  8-spotted  forester. 
— a,  larva ;  b,  an  enlarged  segment ;  c, 
the  moth. 


264  AN   ECONOMIC  ENTOMOLOGY. 

effective,  especially  if  applied  while  the  caterpillars  are  still  quite 
small. 

Arranged  in  the  same  family,  Agaristidcc,  are  several  similar 
caterpillars,  producing  quite  different  moths,  but  amenable  to  the 
same  methods  of  treatment.  One  species,  the  larva  of  Psycho- 
morpha  epimenis,  folds  the  edges  of^  the  leaves  and  lives  in  the 
little  pocket  so  formed  ;  but  they  are  usually  so  rare  that  they  can 
hardly  be  termed  injurious. 

In  that  part  of  the  Southern  States  where  the  "moon-vine," 
Ipomaa,  flourishes,  it  is  often  attacked  and  sometimes  defoliated 
by  a   yellow,   hairy  caterpillar,  which    appears   in   considerable 

Fig.  284.  Fig.  285. 


Psychomorpha  ephnenis.— Male   insect  Iiuc/iyoviia  ipomcecp. 

and  larva. 

numbers.  When  this  is  full  grown  it  denudes  itself  of  hair,  and 
with  it  and  a  few  threads  of  silk  forms  a  bright  yellow  cocoon, 
from  which  issues  in  due  time  a  wasp-like  moth  expanding 
nearly  an  inch,  with  narrow,  white-spotted  black  wings,  and  a 
black,  bright  red  or  yellow  banded  abdomen.  This  is  Ejuhro 
inia  ipom(£ce,  which  flies  rather  heavily  and  clumsily  during  the 
middle  of  the  day  in  bright  sunlight.  As  against  this  insect  the 
arsenites  are  indicated,  or,  where  only  a  few  plants  are  to  be 
protected,  hand-picking  may  be  resorted  to. 

In  vineyards  there  may  be  often  seen  feeding  on  the  under 
sides  of  the  leaves  little,  black-spotted,  yellow,  somewhat  hairy 
larvae,  less  than  half  an  inch  in  length,  ranged  side  by  side  as 
closely  as  possible,  and  retreating  as  they  eat  until  a  leaf  is  com- 
pletely skeletonized.  When  this  kind  of  larva  is  full  grown  it 
spins  a  white,  flattened  cocoon,  in  which  it  changes  to  a  pupa 
and  from  which  it  emerges  in  due  time  as  a  little,  narrow- 
winged,  black  moth  wearing  a  red  collar.     This  is  the  Harrisina 


THE   IXSECT   WORLD.  265 

americana,  and  certain  varieties  of  grapes  are  occasionally  in- 
jured by  its  larva.  Feeding  in  colonies,  as  it  does,  the  insect  is 
easily  checked  by  local  applications  of  the  arsenites. 


Grape-leaf  on  which  larva:-  of  Hai  >  in'iia  aviei  ica>ia  are  feeding. 

We  now  enter  into  a  series  of  species  the  caterpillars  of  which 
are  known  as  "  woolly  bears,"  from  the  fact  that  they  are  all 
clothed  with  long  hair.  In  some  cases  this  hair  is  so  dense  that 
the  body  of  the  caterpillar  itself  cannot  be  seen  at  all,  and  all 
these  are  of  the  Ardiid  series.  They  spin  a  small  quantity  of 
silk  only,  and  use  the  hair  with  which  they  are  clothed  in  con- 
junction with  it  to  form  the  cocoon.  Under  the  microscope  it 
may  be  seen  that  it  is  furnished  with  small  spurs  or  branches,  by 
means  of  which  the  insect  is  able  to  produce  a  felt-like  material, 
needing  only  a  small  quantity  of  silk  to  hold  it  together  in  a 
tissue  sufficiently  firm  for  its  purpose.  Perhaps  the  majority  of 
the  caterpillars  of  this  series  feed  upon  low  plants,  and  frequently 
it  does  not  matter  much  what.  Plantain  seems  to  be  a  common 
food  for  many  species,  but  they  eat  grasses  as  well,  and,  indeed, 
almost  anything.  They  are  often  found  in  gardens  attacking 
lettuce  and  cabbage,  and  on  cabbages  they  are  sometimes  trouble- 
some in  the  field.     Some  are  almost  while  or  yellowish,  and  vary 


266 


AN  ECONOMIC  ENTOMOLOGY. 


to  brown  or  reddish,  sometimes  even  to  blackish,  the  hair  being 
of  the  colors  indicated,  and  the  surface  of  the  body  hardly  visible. 
The  commonest  of  all,  perhaps,  is  the  Spilosoma  virginica,  or 
"white  ermine  moth,"  and  this  is  whitish  or  yellowish,  produc- 
ing a  snow-white  moth,  the  wings  a  little  black  dotted,  the  sides 
of  the  abdomen  and  front  legs  yellow.  Another  species  often 
seen  crawling  about  during  late  fall  is  Pyrrhardia  isabella,  and 

Fig.  287. 


spilosoma  vhginica,  the  wliite  ermine  moth. — ff,  larva;  b,  pupa  ;  <",  adult. 


this  caterpillar  may  be  recognized  by  having  the  central  portions 
of  the  body  red-brown,  while  the  anterior  and  posterior  segments 
are  black.  This  produces  a  uniformly  brownish-yellow  moth. 
All  the  moths  fly  at  night,  and  are  but  rarely  seen  during  the 
day,  and  all  the  caterpillars,  where  they  become  troublesome, 
are  within  reach  of  the  arsenites. 

An  exception  to  the  general  feeding  habit  we  find  in  Hyphan- 
tria  ciinca,  the  caterpillar  of  which  is  known  as  the  "  fall  web- 
worm."  The  moth  is  white,  sometimes  without  spot  or  mark 
of  any  kind,  usually  with  only  a  few  black  dots,  but  occasionally 
with  the  spots  forming  more  or  less  evident  bands  across  the 
wing.  The  eggs  are  laid  in  masses  on  trees,  and  the  larvae,  as 
soon  as  they  hatch,  form  a  little  web  in  which  they  remain  so- 
cially, except  when  feeding.  They  eat  first  the  leaves  within, 
then  those  close  to  their  nest,  gradually  separating  until  some- 
times an  entire  tree  becomes  defoliated  from  a  single  point.    This 


THE    INSECT   WORLD. 


267 


species   often   becomes   a   serious  pest  in  cities  on   shade-trees. 
There  are  two  broods,  the  second  being  usually  the  one  most 


Fig.  288. 


The  fall  web-worm,  Hyphantria  cunea.—a,  b,  c,  varieties  of  larva  ;  d,  e,  pupa  ;  /,  moth  of 
the  normal  white  form. 

noticeable,  whence  the  name  "fall"  web-worm,  to  distinguish  it 
from  the  common  orchard  tent-caterpillar,  which  appears  only  in 

Fig.  289. 


Hyphantria  cunca:  variations  in  the  markings  of  the  wings. 


spring.     A  large  variety  of  trees  and  shrubs  is  attacked   by  this 
insect,  and  where  abundant  it  becomes  a  great  nuisance.     Usu- 


268 


A  A'  ECONOMIC   ENTOMOLOGY. 


ally  its  natural  enemies  keep  it  in  check,  but  sometimes  it  seems 
to  outrun  them,  and  then  for  a  series  of  years  in  succession  it 
becomes  increasingly  abundant  until,  as  suddenly  as  it  increased, 
it  disappears  so  nearly  that  nothing  will  be  seen  of  it  for  a  few 
years.  If  the  insect  is  taken  in  hand  as  soon  as  noticed,  cutting 
down  and  destroying  the  newly  formed  nests  with  all  the  cater- 
pillars they  contain  will  pro\e  the  most  satisfactory  remedy,  or 
the  foliage  just  surrounding  them  may  be  sprayed  with  an  arsen- 
ical mixture. 

There  are  other  species  in  this  series,  like  those  belonging  to 
che  genus  Halisidota,  which  sometimes  infest  shade-trees,  but 
rarely  in  numbers  sufficient  to  be  troublesome.  The  caterpillars 
may  be  distinguished  by  having  slender  pencils  of  hair,  and  some- 
times a  series  of  dorsal  tufts.  The  moths  are  brownish  yellow, 
with  rows  of  semi-transparent  and  irregular,  light-brown  spots 
arranged  almost  in  bands.  Economically  none  others  of  the 
Ardians  are  troublesome,  though  we  ha\'e  many  species  that  are 
common  enough  when  sought  for. 

In  the  family  Lymantriidce  we  have  what  are  known  as  the 
"vaporer, "  or  "tussock  moths."  Of  these  the  Notohphus 
{Orgyid)  leiccostigma,  or  "white-spotted  tussock-moth,"  is 
the  most  common.     It  feeds  on  a  great  variety  of  trees  in  the 

larval    stage,   and    is 


Fig.  290. 


Caterpillar  of  Notolophus  leucosligiiia. 


seriously  troublesome 
in  cities  and  towns. 
The  caterpillars  are 
rather  pretty  creat- 
ures, with  bright  red 
heads  resembling 
sealing-wax  in  ap- 
pearance, and  yel- 
low bodies  bearine  a 


series  of  dense,  abruptly  cut  oft"  brushes  on  the  middle  of  the 
back,  and  two  pencils  of  black  hair  anteriorly.  They  are  rather 
more  than  an  inch  in  length,  when  full  grown  crawl  down  the 
trees,  and,  either  on  the  trunk  or  somewhere  in  the  vicinity,  under 
any  projecting  point  on  fence-rail  or  the  like,  make  their  dirty- 
whitish  cocoon  of  mixed  silk  and  hair.  In  due  time  the  adults 
emerge,  the    male   bearing   fully  developed    wings,    while    the 


THE    IXSECT    WORLD. 


269 


female  has  no  trace  of  tlieni  whatever.  Tlie  wings  of  the  male 
are  dusty  gray  in  color,  crossed  by  rather  distinct,  blackish  lines, 
and  with  a  little  white  spot  near  the  outer  lower  angle,  which 
gives  the  insect  its  name,  Icucostigma.  The  antennae  are  prom- 
inently feathered  or  pectinated,  and  the  forelegs  are  long,  very 
prettily  tufted,  and  held  when  at  rest  projecting  some  distance 
forward.  The  insect  is  not  often  seen  during  the  day,  and  usu- 
ally rests  concealed  until  nightfall,  when  it  seeks  its  mate.  The 
female  can  be  distinguished  in  the  pupal  stage  by  its  larger  size 
and  the  absence  of  wing  pads.  When  it  crawls  out  upon  the 
surface  of  its  cocoon  it  is  a  grub-like  creature  with  a  very  heavy 

Fig.  291. 


The  vaporer  moth,  Xotoloplitis  Irncostigma.—a,  wingless  female  on   her  egg-mass  ;    b, 
young  larva  ;  c,  female,  d,  male  pupa ;   e,  male  moth. 

body,  rather  short  legs,  small  head,  and  very  short  antennse. 
Neither  of  the  sexes  are  capable  of  feeding,  and  as  soon  as  the 
male  has  found  the  female,  oviposition  begins.  The  eggs  are 
deposited  upon  the  cocoon  from  which  the  female  emerged,  and 
as  laid  they  are  covered  with  a  snow-white,  frothy  mass  which 
hardens  almost  immediately  into  a  brittle  material  that  serves  as 
a  protection.  The  first  brood  of  moths  appears  about  midsum- 
mer, and  from  the  eggs  then  laid  the  little  caterpillars  hatch  in  a 
few  days  ;  these  in  turn  become  adult  in  fall,  and  eggs  then  laid 
remain  throughout  the  winter,  the  prominent  white  masses  soon 
turning  gray  and  dirty,  and  hardly  conspicuous  on  the  trees  or 
other  surroundings  to  which  they  are  attached.  In  the  more 
northern  States  there  is  a  single  brood  only.  These  insects  when 
troublesome  to  shade-trees  are  easily  dealt  with  :  if  all  the  egg- 
masses  are  removed  and  destroyed  during  the  winter,  the  tree 
will  remain  clean  during  the  ensuing  summer,  provided  caterpillars 


270 


AN   ECONOMIC    ENTOMOLOGY. 


are  prevented  from  crawling  up  the  trunk  from  the  surrounding 
points.  A  band  of  "  dendrolene"  six  inches  in  width  and  half  an 
inch  thick  on  a  sheet  of  heavy  wrapping-paper  will  serve  as  a 
complete  protection  if  the  tree  has  been  cleared  of  eggs  during  the 
preceding  winter.  It  is  easy  to  see  how  this  is  done  ;  the  female 
is  absolutely  incapable  of  flight,  and  no  eggs  can  be  laid  upon  a 
tree  until  a  caterpillar  has  first  made  its  way  upon  it  and  has 
changed  to  a  female  moth.  Instead  of  "  dendrolene  "  a  broad 
band  of  fluffy  cotton  will  answer  for  a  time,  as  the  caterpillars 
become  entangled  in  and  are  unable  to  cross  it.  This  sort  of 
protection  must  be  carefully  watched,  however,  because  other- 
wise the  wet  and  dirt  will  harden  and  cause  its  failure  to  act  as  a 
bar.  A  trough  of  oil  or  an  inverted  tin  cone  tightly  fixed  to  the 
tree  may  also  serve,  as  will  anything  else  that  prevents  the  cater- 
pillars from  crawling  upon  the  tree. 

Belonging  about  here  in  the  series  comes  the  European 
"gypsy  moth,"  Oaieria  dispar,  which,  imported  into  Massa- 
chusetts in  1868,  has  caused  enormous  damage  in  that  State,  and 
has  cost  annually  many  thousands  of  dollars  to  keep  it  in  check. 
The  caterpillar  when  full  grown  is  about  one  and  one-half  inches 
in  length,  of  a  creamy  white,  so  thickly  sprinkled  with  black  that 
it  seems  dark  brown,  the  ground  color  appearing  in  the  broken 
dorsal  and  lateral  lines.  It  is  furnished  with  distinct  dorsal  and 
lateral  tubercles,  blue  anteriorly  and  crimson  behind  the  fifth 
segment,  from  each  of  which  arise  tufts  of  long  black  and  yel- 
lowish hair.  It  changes  to  a  chocolate-brown  pupa,  held  in  place 
by  a  few  threads  forming  the  merest  apology  for  a  cocoon,  from 
July  to  September,  and  a  few  days  thereafter  the  moths  emerge. 
The  males  expand  from  one  and  one-half  to  two  inches,  are 
brownish  yellow  in  color,  the  secondaries  paler  with  a  darker 
outer  margin,  the  primaries  smoky  with  darker,  irregular,  trans- 
verse lines.  The  females  are  much  larger  and  more  heavily 
built,  the  wings  often  expanding  two  and  one-half  inches.  They 
are  creamy  white  in  color,  the  irregular,  transverse  lines  gray  or 
blackish.  They  lay  their  eggs  in  masses  of  from  four  hundred  to 
five  hundred  in  all  conceivable  localities,  and  cover  them  with 
yellow  hair  and  scales  from  the  end  of  the  abdomen.  They  are 
deposited  from  July  to  late  in  September,  and  the  larvae  hatch 
early  the  following  year,  ranging  from  April  to  June,  according 


THE    /A  SECT    WOK  I.  P. 


271 


to  temperature  and  location.  The  fight  against  this  insect  is  told 
in  the  reports  of  the  Gypsy  Moth  Commission  of  Massachusetts, 
and  these  have  been  distributed  wherever  the  insect  has  made  its 
appearance.  It  has  not  as  yet  extended  beyond  Massachusetts  ; 
hence  details  as  to  its  destruction  are  not  in  place  here.  It  is, 
perhaps,  the  most  dangerous  i)est  ever  introduced  into  the 
United  States,  and  should  the  State  of  Massachusetts  abandon  its 
campaign  against  it,  the  annual  charge  upon  the  farmers  of  the 
country  would  become  enormous,  if  not  ruinous. 

To  the  family  Euclcidcc,  or   Limacodidcc,  belong  a  series  of 
rather  modest  green  and  brown  moths,  usually  small  in  size,  very 

Fig.  296. 


The  saddle-back  caterpillar  and  its  moth,  Empyctia  slimiilca. 

densely  clothed  with  scales  and  hair,  the  head  much  reduced, 
and  the  tongue  wanting.  This,  by  the  bye,  is  quite  a  general 
character  in  the  types  now  under  consideration,  and  which  are 
termed  "spinners,"  because  most  of  the  caterpillars  make  a 
more  or  less  complete  cocoon  of  silk.  The  Liiiiacodids  are  rarely 
common,  and  only  one  species,  Empretia  stimidca^  has  become 
troublesome  in  the  caterpillar  state.  This  is  a  very  curious,  slug- 
like larva,  somewhat  flattened  and  oblong  in  shape,  most  of  the 
body  green  in  color,  but  with  a  quadrate,  red-brown  patch 
resembling  a  saddle  on  the  middle  of  the  back,  and  a  brown 
patch  at  each  end  of  the  body,  from  the  outer  edge  of  each  of 
which  arises  a  long,  fleshy  process,  set  with  stiff"  spines  in  all 
directions.  Small  warts  or  processes  are  found  along  the  sides 
of  the  body,  set  with  stiff"  hairs  in  the  same  way.     It  has  no  ap- 


272 


AN  ECONOMIC  ENTOMOLOGY. 


Fig.  297. 


A  tubercle  from  a  saddle-back  moth,  Emf>rrtia  slimulea,  showing  the  poisonous  spines,  very 
much  enlarged.     The  short  pointed  tips  break  off  readily  and  remain  in  the  wound. 


THE    IXSECT    WORLD. 


273 


parent  legs,  but  seems  to  crawl  directly  upon  its  belly,  as  do  all 
the  other  caterpillars  of  this  family,  most  of  which  have  similar, 
though  less  developed,  spinous  processes.  Another  peculiarity 
which  this  species  shares  with  others  in  the  family  is,  that  when 
handled,  it  causes  a  burning  pain  as  if  nettles  had  been  touched. 
The  hollow  spines  are  terminated  with  easily  detachable,  very 
short,  stiff  tips,  and  at  their  base  is  a  gland  which  secretes  an 
urticating  liquid.  Handling  the  caterpillars  roughly  results  in 
breaking  off  the  little  tips,  which  enter  the  skin  and  at  the  same 
time  release  a  little  drop  of  liquid,  which,  entering  the  wound, 
causes  the  burning  sensation.  With  some  persons  this  becomes 
a  serious  matter  ;  first  inflammation,  then  swelling  sets  in,  and  in 
extreme  cases  a  numbness  or  partial  jjaralysis  of  the  entire  limb 
ensues.  As  a  rule,  however,  the  irritation  is  local,  and  no  worse 
than  would  result  from  handling  a  nettle.  The  prompt  applica- 
tion of  ammonia,  bicarbonate  of  soda,  or  even  strong  brine 
will  generally  act  as  an  antidote.  This  saddle-back  caterpillar 
lives  on  a  great  variety  of  plants,  including  pear  and  rose,  on 
which  it  is  sometimes  found  in  numbers.  When  full  grown  it 
spins  an  oval,  brown,  parchment-like  cocoon,  and  in  this  remains 
unchanged  until  spring  ;  then  it  transforms  to  a  pupa,  and  from 
this  issues  a  brown  moth,  expanding  less  than  an  inch,  and 
known  as  Empretia  stimulea.  A  number  of  other  caterpillars  of 
this  family  attack  fruit-trees,  but  always  in  such  small  numbers 
that  they  can  hardly  be  considered  injurious. 

The  family  Psychidce  is  peculiar  in  that  the  larvae  are  encased 
in  sac-like  structures  which  they  carry  about  with  them,  and 
from  which  they  derive  the  common  term  "bag-worms."  The 
best  known  of  these,  "the"  bag-worm,  is  Thyridoptoyx  ephcm- 
erceforinis.  This  is  often  common  in  orchards,  and  also  attacks 
shade-trees,  but  is  perhaps  m.ost  injurious  on  arbor-vitae  hedges, 
which  it  sometimes  kills.  On  deciduous  trees  the  insects  are 
usually  noticed  during  the  winter,  when  there  may  be  found 
hanging  to  the  twigs  and  branches  cone-shaped  bags  of  silk 
varying  from  a  little  less  than  an  inch  to  an  inch  and  a  quarter  in 
length,  and  studded  with  bits  of  sticks  and  leaves.  If  the 
smaller  of  these  bags  are  cut  open  at  this  time  there  will  be  found 
an  empty  pupa  shell,  but  in  the  larger  there  will  be  found  a  mass 
of  yellow,  fluffy  material  embedded  in  which  is  a  great  mass  of  eggs. 

18 


274 


A/^   ECONOMIC   ENTOMOLOGY. 


In  the  spring  these  eggs  hatch,  and  the  httle  larvae  make  their 
way  out  through  the  mouth  of  the  bag  and  feed  upon  the  leaves, 
at  once  constructing  for  themselves  a  case  made  of  leaf  fragments 
held  together  with  silken  threads.  At  this  time  the  bags  are 
carried  upright,  and  the  insects  feed  on  the  upper  surface  of  the 
leaf  As  the  larva  grows  it  enlarges  its  habitation,  which  soon 
becomes  too  heavy  to  be  maintained  in  an  upright  position,  and 


Fig.  298. 


The  bag- worm,  Thyridopteryx  ephi'meriTfoymis. — a,  larva;  b,  male  pupa;  c,  female; 
d,  male  moth  ;  c,  bag  of  female  cut  open  to  show  the  mass  of  eggs  ;  f,  caterpillar  with 
bag  in  normal  position  ;  g,  young  larvae  with  bags  carried  upright. 


drops  ;  the  insect  continues  to  feed,  attaching  the  bag  by  means 
of  silken  threads  to  twigs  when  not  moving  about  from  place  to 
place.  Late  in  summer  the  larvae  become  full  grown,  and 
wander,  sometimes  leaving  the  trees  altogether  and  fastening  to 
fences  or  other  shelter  in  the  vicinity,  and  it  is  this  habit  that 
provides  for  the  .spread  of  the  insects.  When  they  have  reached 
a  place  that  suits  them,  the  bags  are  firmly  fastened,  the  opening 
is  closed,  and  the  caterpillars  change  to  pup^e.  Shortly  after  the 
male  emerges,  and  this  is  a  black  moth  with  transparent  wings, 
short,  feathered  antennae,  and  an  unusually  long,  tapering  body. 
It  is  quite  active  and  seeks  the  female,  which  forms  only  an 
imperfect  sort  of  pupa,  and  even  in  the  adult  condition  is  a  non- 
descript without    trace  of  wings  and  almost  without  antennae. 


THE    INSECT   WORLD. 


275 


It  is,  indeed,  a  helpless,  grub-like  creature  that  awaits  the  visit 
of  the  male  without  making  an  attempt  to  emerge  from  its  sac, 
in  wliich  it  remains  even  after  impregnation.     The  eggs  develop, 
finally  fill  up  the  bag,  and  then 
the  female  dies,  the  eggs  rest-  ^^'^■ 

ing  in  the  fluffy  mass  already 
described  until  the  spring  fol- 
lowing. 

This  species  is  best  treated 
by  picking  off  and  destroying 
the  bags  during  the  winter,  and 
if  this  is  thoroughly  done  no 
caterpillars  will  appear  on  the 
trees  in  the  spring,  unless  they 
crawl  on  from  other  points 
where  an  egg-sac  may  happen 
to  be  attached.  The  meas- 
ures recommended  against  the 
"white-marked  tussock  moth" 
can  be  employed  here  as  well, 
and  trees  once  cleared  can  be 
kept  free  without  much  diffi- 
culty. When  arbor-vitae  is  at- 
tacked, the  picking  should  be 
thoroughly  and  carefully  done,  because  these  hedges  suffer  very 
rapidly,  and  once  defoliated,  usually  die.  In  orchards  where 
spraying  is  done  against  the  codling-moth,  the  "bag-worms" 
are  destroyed  incidentally  and  no  special  measures  need  be  taken 
against  them. 

Next  follows  the  family  of  "  prominents,"  so  called  from  the 
fact  that  the  moths  frequently  have  a  tooth  at  the  inner  margin 
of  the  fore  wings,  and  the  caterpillars  are  sometimes  a  little 
humped.  They  are  technically  termed  NotodontidcE.  Most  of 
then}  have  a  small,  retracted  head,  many  of  them  a  short  or 
obsolete  tongue,  and  some  are  more  or  less  troublesome  on  cul- 
tivated plants. 

One  of  the  best  known  is  the  "yellow-necked  caterpillar" 
often  found  feeding  on  apple-trees  in  colonies  of  from  fifty  to 
more  than  one  hundred.     When  full  grown  it  is  nearly  two  inches 


The  bag-worm.— a,  sack  of  female  cut 
open  to  show  the  grub-like  creature  at  its 
mouth  ;  b,  the  female  removed  from  the 
bag,  much  enlarged. 


276 


AN   ECONOMIC  ENTOMOLOGY. 


in  length,  with  a  black  head,  a  yellow  neck,  and  the  rest  of  the 
body  yellow  and  black  spotted.  It  has  a  peculiar  habit  of  hold- 
ing by  the  false  legs  only  and  dropping  the  head  and  anal  seg- 
ments when  at  rest.  The  insects  feed  very  rapidly  and  often 
defoliate  large  branches  before  their  presence  is  realized.  When 
full  grown  they  descend  to  the  ground,  burrow  a  short  distance 
beneath  the  surface,  forming  a  conical  pupa,  and  remain  in  that 
condition  during  the  winter.  In  spring  the  moths  emerge,  and 
are  of  a  brownish-yellow  color,  crossed  by  rather  even,  narrow. 


Fig.  300. 


The  yellow-necked  caterpillar,  a;  its  parent,  Datana  ministra,  at  b ;  eggs,  natural  size 
and  enlarged,  at  c  and  (/. 

brown  lines  ;  and  this  species  is  Datana  viinistra.  It  lays  its 
white  eggs  to  the  number  of  nearly  one  hundred  on  the  under 
side  of  apple  and  other  leaves  in  a  single  layer.  Similar  cater- 
pillars may  be  found  on  a  variety  of  other  plants.  The  sumach 
is  often  defoliated,  walnut-  and  oak-trees  have  their  own  species, 
and  in  all  cases  the  moths  have  the  general  appearance  already 
described.  Insects  that  feed  thus  in  company  are  controlled 
without  difficulty,  if  we  attack  them  as  soon  as  the  colony  has 
hatched.  They  are  then  confined  to  a  few  leaves,  and  if  these 
be  picked  off"  and  destroyed,  injury  is  avoided  for  the  season.  If 
this  is  not  possible,  or  the  colony  has  already  spread  too  great  a 
distance,  then  spraying  the  infested  brancli  with  arsenites  will 
answer  every  purpose. 

There  are  other  caterpillars  of  this  family  that  attack  fruit-trees, 
but  as  a  rule  in  such  small  numbers  as  to  be  harmless. 

Oak-trees  are  occasionally  attacked  and  defoliated  by  cater- 
pillars about  an  inch  and  a  quarter  in  length,  with  a  yellow  head, 


Fic.  304. 


V\G.    295. 


Kig.  292.  larva  oT  iJMisy  iimlli.  Fij;.s.  294,  295,  gypsy  iiiolli.  (I  iirria  disfiar,  male  ami 
fcinali-.  Fig.  304^  Aniiula  sciia/uria,  larva.  Figs.  305,  306.  .liiisu/u  sciuitoria,  iiuilu  and 
female. 


THE    IXSECT    WORLD. 


277 


the  body  striped  with  narrow  black  or  reddish-brown  hnes,  ex- 
cept at  the  sides,  where  it  is  gray  or  yellowisli.  Near  the  pos- 
terior extremity  is  a  rather  prominent,  humped  segment  entirely 
red  in  color.  When  full  grown  they  go  underground,  and  from 
them  come,  in  the  spring 
following,  moths  gray  in 
color,  mottled  with  brown, 
but  the  front  of  the  body 
and  a  margin  along  the 
anterior  edge  of  the  fore- 
wings  white  or  nearly  so. 
These  are  called  Edema 
albifrons.  The  body  is 
rather  cylindrical,  heavy, 
extending  somewhat  be- 
yond the  hind  wings 
and   obtusely  terminated. 

Feeding  exposed  as  these  insects  do,  they  are  readily  destroyed 
by  the  arsenites. 

One  other  caterpillar  sometimes  occurs  in  swarms  on  a  great 
variety  of  plants,  including  some  fruit-trees,  and  this  is  known 
as  the  "red-humped  prominent."  It  is  yellowish  brown  in 
color,  pale  along  the  sides  and  striped  with  slender  black  lines. 
The  fourth  segment  is  humped  and  of  a  red  color  like  that  of  the 

Fig.  302. 


Ediiiia  albi/rinis  ami   its  larva 


CEdemasia  conciiiua  and  its  larva,  the  "  red-humped  prominent." 


head.  There  are  a  number  of  short  spinous  processes  along  the 
back,  and  some  which  are  larger  and  more  prominent  on  a  hinder 
segment.  The  moth  that  emerges  from  this  larva  is  the  CEdem- 
asia co7icinna,  and  is  of  a  light-brown  color,  the  wings  expand- 
ing a  little  more  than  an  inch,  the  anterior  pair  dark  brown  along 
the  inner  margin  and  more  or  less  gray  tinged  before.     The 


278  AN   ECONOMIC  ENTOMOLOGY. 

measures  already  recommended  are  applicable  to  this  species, 
and  in  fact  none  of  the  caterpillars  belonging  to  this  family  need 
ever  cause  serious  trouble  or  difficulty  in  their  control. 

Next  come  the  Ceratocampida",  containing  only  a  few  very 
large  species  whose  caterpillars  are  more  or  less  furnished  with 
horns,  spines,  or  similar  processes.  The  moths  are  sometimes 
contrastingly  colored  and  distinguished  by  having  the  antennae 
in  the  male  feathered  for  only  a  portion  of  the  distance  ;  the  ter- 
minal third  of  the  stalk  lacking  the  pectinations,  while  towards  the 
base  there  are  two  branches  to  every  joint. 

Occasionally  we  see  a  very  large,  green  caterpillar,  with  black 
and  red  blotches,  and  with  four  very  long  horns,  yellow  at  the 
base  and  black  at  the  tip,  on  the  first  segments.  This  is  an 
insect  much  dreaded,  and  known  by  the  attractive  name  of  "  the 
hickory  horned  devil."  The  first  part  of  the  name  is  from  the 
food  plant  upon  which  it  is  often  found,  the  second  from  its  prom- 
inent horns,  and  the  third  from  its  supposed  evil  inclinations. 
Yet  the  creature  is  absolutely  harmless,  incapable  of  inflicting  the 
slightest  injury  upon  even  the  most  delicate  subject,  and  it  de- 
pends for  protection  entirely  upon  its  formidable  appearance. 
The  moth  resulting  from  it,  atheroma  rega/is,  or  "  regal  wal- 
nut-moth," is  rare  and  seldom  seen,  flying  only  at  night  and  not 
much  then,  because,  having  no  tongue,  it  does  not  feed.  It  is, 
however,  rather  handsome,  tawny  brown  in  color,  the  veins 
streaked  with  red  and  with  two  series  of  more  or  less  distinct 
yellow  blotches.  It  expands  from  three  to  nearly  six  inches,  and 
is  one  of  the  largest  of  our  night-flying  moths. 

The  species  belonging  to  the  genus  Anisota  are  sometimes 
much  more  abundant,  and  occasionally  become  troublesome  on 
oaks.  I  have  seen  acres  of  forest  almost  entirely  defoliated  by 
large  yellow  and  black-striped  caterpillars,  with  black  head,  two 
long,  black  filaments  on  the  anterior,  and  numerous  shorter 
black  processes  on  the  other  segments.  These  are  the  ' '  orange- 
striped  oak-worms,"  which,  when  mature,  go  beneath  the  sur- 
face of  the  ground,  change  to  brown,  roughened  pupae,  and  in 
spring  appear  as  brown  moths  ;  the  Anisota  senatoria.  The  males 
are  much  the  smaller,  have  the  fore-wings  somewhat  triangular 
and  pointed,  a  little  transparent  towards  the  middle,  and  with 
a   clear  white    spot   near   the    centre.     The  females  are  rather 


THE    INSECT    WORLD. 


279 


lighter  in  color,  the  white  spot  is  much  sinaller,  and  the  wings 
arc  not  in  the  least  transparent,  but  irrorated  witli  darker,  small 
spots,  which  give  them  a  powdered  appearance. 

On  maples,  especially  in  the  more  southern  States,  we  often 
find  a  smaller  caterpillar,  which  js  green,  with  black  stripes,  and 
marked  with  little  red  dots.  The  resulting  moth  is  known  as 
the   "rosy  Dryocampa,"   and  has  the  fore-wings  rose  colored. 

Fig.  307. 


Dryocampa  rubicunda. — a,  its  larva  ;  b,  its  pupa  ;  r,  female  moth  :  the  rosy 
Dryocampa. 


crossed  by  a  broad  pale-yellow  band,  while  the  hind  wings  are 
pale  yellow,  with  a  short  rosy  band  behind  the  middle.  It  is 
rarely  abundant  enough  to  need  attention,  but  when  it  does,  the 
external  feeding  habit  indicates  the  remedy  at  once. 

Next  we  reach  the  series  of  species  that  are  silk-spinners  par 
excellence  in  the  caterpillar  state.  They  are  known  in  a  general 
way  as  bombycids  from  the  term  Bonibyx^  which  was  for  a  long 
time  applied  to  the  "silk- worm."  Among  the  largest  of  our 
Lepidoptera  are  the  species  of  Attacus,  which  expand  from  four 
to  eight  inches,  and  are  allied  to  the  giants  of  the  tropical  region, 
which  have  a  spread  of  wing  of  sometimes  fully  twelve  inches. 
None  of  our  species  are  ever  numerous  enough  to  be  really 
troublesome,  and  they  are  interesting  rather  from  the  habits  of 
the  caterpillars,   which,  before   changing  to  pupae,   spin  a  very 


28o 


A.V  ECONOMIC  ENTOMOLOGY. 


large  and  dense  cocoon  of  silk,  in  which  they  remain  until  ready 
to  transform  into  moths.     The  most  common  of  these  spinners 


is  the  cecropia,  Platysamia  cecropia,  the  caterpillar  occurring  on 
a  great  variety  of  plants,  including  many  of  our  fruit-trees  and 


THE    INSECT  WORLD.  281 

certain  small  fruits.  It  is  green,  and  has  six  rather  j)roniinent 
warts  on  the  thoracic  segments,  of  which  four  are  coral-red  in 
color  and  the  hinder  two  are  yellow,  sometimes  with  a  reddish 
tinge.  On  the  rest  of  the  body  are  other  tubercles  which  are 
furnished  with  little  clusters  of  spurs  and  spines.  The  cocoon  is 
sometimes  spun  in  bushes,  attached  to  a  twig,  sometimes  at  an 
angle  of  a  fence,  or  wherever  the  caterpillar  happens  to  consider 
it  convenient.     The  resulting  moth  is  dusky  brown  and  powdery, 

Fig.  309. 


Caterpillar  of  the  cecropia  moth. 


tlie  hinder  margins  clay-colored,  a  kidney-shaped  dull-red  spot 
with  a  white  centre  and  a  narrow  black  edging  is  near  the 
middle  of  each  wing,  and  beyond  the  spot  is  a  wavy  dull-red 
band,  bordered  internally  with  white.  The  primaries  near  the 
base  are  dull  red,  and  near  the  tip  is  an  eye-like  black  spot  within 
a  bluish-white  crescent.  Several  other  species  occur,  all  more 
or  less  resembling  in  general  appearance  the  cecropia,  and  spin- 
ning much  the  same  kind  of  cocoon. 

Of  a  somewhat  different  type  is  the  polyphemus,  Telea  poly- 
phennis,  which  has  a  green  caterpillar  without  prominent  tuber- 
cles, but  with  little,  black,  wart-like  processes,  giving  rise  to 
small,  stiff  bristles.  This  feeds  upon  oak  and  a  variety  of  other 
trees,  but  is  rarely  abundant,  and  when  forming  its  cocoon  spins 
np  in  a  leaf,  which  later  drops  to  the  ground.  This  cocoon  is 
o^-al  in  shape  and  completely  closed,  differing  from  that  of 
cecropia  and  its  nearest  allies,  in  which  it  is  open  at  one  end. 


282 


A,V  ECONOMIC  ENTOMOLOGY. 


Fig.  310. 


The  moth  is  dull  ochre-yellow  in  color,   more   or  less  clouded 
with  black  in  the  middle  of  the  wings,  on  each  of  which  there 

is  a  transparent  eye-like  spot,  divided 
transversely  by  a  slender  line  and  en- 
circled by  yellow  and  black  rings. 
Before  and  adjoining  this  spot  in  the 
hind  wings  is  a  large  blue  patch 
shading  into  black. 

With  a  very  similar  caterpillar  and 
cocoon,  the  luna  moth,  Adias  hma, 
is  entirely  different  from  the  poly- 
phemus.  It  is  of  an  even,  bluish-green 
color,  sometimes  verging  into  yellow- 
ish, with  a  little  eye-like  spot  on  all 
wings,  the  anterior  border  of  the  fore- 
wings  margined  with  scarlet,  while  the 
hind  wings  are  each  furnished  with  a 
long  tail. 

When  these  caterpillars  are  noticed 
on  a  cultivated  plant  they  can  be 
easily  picked  off  and  destroyed,  but 
as  a  rule  their  natural  enemies  serve 
to  keep  them  reduced  to  compara- 
tively small  numbers.  These  Ameri- 
can species  produce  a  much  greater 
quantity  of  silk,  of  a  much  stouter 
texture  than  the  Chinese  silk-worm 
proper ;  but,  unlike  it,  their  thread 
cannot  be  reeled.  It  is  this  that  makes 
it  impossible  to  use  our  species  suc- 
cessfully for  the  production  of  a  cheap 
and  strong  silken  fabric. 

We  sometimes  find  on  corn,  clover, 
apple,  and  other  plants  or  trees  a 
green  caterpillar,  with  a  brown  stripe  edged  with  white  on  each 
side  of  the  body,  covered  also  with  little  processes,  from  which 
arise  clusters  of  prickly  spines.  These  have  urticating  proper- 
ties, so  that  if  the  larvae  are  carelessly  handled  a  certain  amount  of 
irritation  may  arise,  though  much  less  than  is  the  case  with  the 


Cocoon  of  the  cecropia  moth. 


THE    IXSECT   WORLD. 


283 


slug-like  cateri^illars  j)reviously  described.     They  become  rather 
more  than  two  inches  in  length,  spin  a  thin,  irregular,  and  some- 


what parchment-like  cocoon,  and  emerge  in  due  time  as  "  io" 
moths,- — Automcris  i^Hyperchirid)  io.      The  male  is  deep  yellow, 


284  -^^^^   ECONOMIC   ENTOMOLOGY. 

the  primaries  only  a  little  banded  with  narrow  lines,  the  wings 
reddish  on  the  interior  margin,  with  a  narrow  band  of  the  same 

color    outwardly.       On    the 
Fig.  312.  middle  of  the  hind  wing  is  a 

large,  round,  blue  spot,  with 
a  broad  black  border  and 
a  central  white  dash.  In 
the  female  the  primaries  are 
purple-brown,  the  transverse 
lines  gray  and  much  more 
prominent,  and  there  is  a 
somewhat  dusky,  pale-mar- 
gined, nearly  kidney-shaped 
discal  spot.  The  hind  wings 
are  essentially  like  those  of 
the  male,  and  altogether  this 
sex  is  larger  than  its  com- 
panion. 

The  only  other  of  the  silk- 
spinners  to  which  attention 
need  be  called  here  are  the 
species  of  Clisiocainpa,  which  are  interesting  from  the  fact  that 
most  of  them  live  in  colonies  and  spin  a  tent  of  silk  on  the  trees 

Fig.  313. 


Larva  of  io  moth. 


Auto»ie)  is  io,  female. 


attacked  by  them,  whence  they  are  called   "tent-caterpillars." 
Our  common  species  in  the  East  is  C.  aniericana,  found  in  apple 


THE    IXSECr    WORLD. 


285 


orchards  very  early  in  the  spring.  During  the  winter  we  often 
find  on  the  small  twigs  of  the  apple  an  incomplete  belt  of  a 
\'ery  dark  brown,  wax- 
like material.  If  we  ^'^-  ^'4- 
examine  this  carefully 
we  find  it  to  consist  of 
a  very  large  number  of 
eggs  soldered  together, 
from  which  caterpillars 
hatch,  sometimes  be- 
fore the  leaves  have 
started,  which  at  once 
spin  a  litvle  web  or  tent 
in  the  nearest  fork. 
Here  they  live  in  com- 
pany, moving  out  from 
time  to  time  to  feed 
upon  the  surrounding 
leaves,  and  increasing 
the  size  of  their  habita- 
tion as  they  grow.  The 
"tents"  form  promi- 
nent and  unsightly 
objects  in  neglected 
orchards,  and  are  some- 
times rather  unpleas- 
antly conspicuous  in 
others  that  purport  to 
be  well  kept.  When 
full-grown  the  cater- 
pillars abandon  the 
nest,  crawl  to  some 
convenient  shelter  in 
the  vicinity,  and  spin  a 
yellow,  rather  thin  cocoon,  which  becomes  covered  with  a  fine 
yellow  powder.  The  moth  is  dull  reddish  in  color,  more  or  less 
brown-tinged,  and  the  fore-wings  have  two  oblique,  pale  stripes. 
'Hie  males  are  considerably  smaller  than  the  females,  and  as  a 
rule  darker  in  color,  tending  to  have  the  wing  between  the  lines 


The  American  tent-caterpillars,  a  and  b,  on  the  out- 
side of  their  tent  near  the  entrance ;  d,  cocoon  ;  c, 
egg-mass  of  an  allied  species ;  above  all  the  female 
moth,  Clisiocanipa  ainericaiia. 


286  AN    ECONOMIC    ENTOMOLOGY. 

paler,  while  in  the  female  we  have,  on  the  whole,  an  opposite 
tendency.  In  the  West,  other  species  replace  the  americana, 
but  their  habits  remain  essentially  the  same,  and  they  may  be  all 
treated  in  the  same  manner.  During  the  winter  the  egg-masses 
are  easily  seen  after  a  little  practice,  and  they  can  generally  be 
reached  and  cut  down  without  trouble.  Early  in  spring  the 
nests  are  prominent  objects  and  easily  destroyed,  with  the  entire 
colony.  Where  they  are  out  of  easy  reach,  simply  spraying  the 
branches  nearest  to  their  nest  will  destroy  them  in  a  day  or  two. 
In  orchards  in  which  spraying  is  systematically  done  for  other 
pests,  these  insects  rarely  get  a  foothold. 

The  true  silk-worm,  Sericaria  mori,  though  economically  im- 
portant, is  hardly  a  proper  subject  for  this  work.  Its  history  is 
so  well  known,  and  has  so  many  special  books  devoted  to  it, 
that  it  is  unnecessary  to  go  into  details  here. 

In  the  family  Cossidce  we  have  a  series  of  very  peculiar  moths, 
really  low  in  the  scale  of  development,  but  formerly  placed  about 
here  in  the  classification  and  conveniently  so  treated.  The  cater- 
pillars are  all  wood-borers,  living  from  two  to  four  years  in  the 
trunks  or  roots  of  trees.  They  are  white,  or  with  a  faint  red  or 
yellow  tinge,  more  or  less  black  spotted,  and  with  short,  bristly 
hairs.  The  head  is  large  and  horny,  usually  black,  and  the  jaws 
are  stout  and  prominent.  When  full-grown  they  are  from  two 
to  three  inches  in  length,  and  change  to  a  rather  slender,  cylin- 
drical pupa  an  inch  to  an  inch  and  a  half  in  length,  depending 

upon    the   species    and    sex. 
Fig.  319.  This  pupa  is  furnished  with  a 

series  of  spines  around  the 
edges  of  each  segment  and 
sometimes  also  with  a  chisel- 
Pupa  of  the  goat-moth.  ^i^e  protuberance  on  the  head- 
case.  When  ready  to  trans- 
form, it  works  itself  by  a  twisting  and  wriggling  motion  through 
the  bark  and  for  half  its  length  out  into  the  open,  holding  fast 
by  the  spines  on  the  abdominal  segments.  The  adults,  known  as 
"goat-moths,"  from  a  rank  odor  peculiar  to  them,  have  rather 
narrow,  pointed  wings  and  a  long  conical  abdomen.  The 
females  are  heavy  fliers,  and  both  sexes  are  attracted  to  light, 
though  rarely  seen  otherwise.     The  head    is  small,   very  much 


THE    INSECT    WORLD. 


287 


retracted,  and  the  tongue  is  obsolete,  so  that  the  insect  is  in- 
capable of  feeding.  None  of  our  American  species  attack  culti- 
vated plants  or  trees  so  as  to  become  injurious,  though  in  forests 

Fig.  320. 


Goat-moths,  Prionoxystus  robiniie,  female  and  male,  and  their  larva. 


young  oak  timber  is  sometimes  badly  injured  by  the  Prionoxys- 
tus robinicB. 

There  has  been  recently  introduced  into  the  Eastern  United 
States  a  European  species  known  as  the  leopard-moth,  Zeuzera 
pyrina,  and  this  has  become  a  pest  on  the  shade-trees  in  several 
of  our  Eastern  cities.  The  male  moths  expand  a  little  more  than 
an  inch,  the  female  over  two  inches,  and  both  are  white,  spotted 
with  black,  whence  the  common  name  "  leopard-moth."  There 
is  great  difficulty  in  dealing  with  insects  of  this  character,  owing 
to  their  food  habits.  Fortunately,  even  in  this  imported  form, 
the  natural  checks  seem  to  prevent  its  doing  much  injury  to 
orchards  or  country  trees  ;  but  in  the  cities  and  towns  it  threat- 
ens the  life  of  the  shade-trees.     The   onlv  recommendation  to 


288 


^A'    ECO  NO  All  C   ENTOMOLOGY. 


be  made  is  constant  watching  by  some  man  especially  employed, 
who  will  destroy  the  borers  just  as  soon  as  their  presence  is 
noticed,  and  who  will  gather  the  moths  beneath  the  electric  lights 
now  found  in  most  cities.  Pans  in  which  oil  or  some  other  sub- 
stance is  kept  to  kill  the  insects  falling  into  them,  properly 
arranged  just   beneath    the   lights,    will    prove   of   considerable 

Fig.  321. 


The  wood  "leopard-moth,"  Zeiizera  pyrina. — a,  b,  larva,  from  above  and  side,  about 
half  grown;  c,  male,  rf,  female;  e,  larval  burrow,  showing  the  tendency  of  the  full- 
grown  caterpillar  to  girdle  its  food  plant. 

benefit ;  but  it  will  take  years  of  steady  work  to  lessen  the  insects 
in  some  of  our  cities,  and  to  remove  them  as  a  source  of  danger 
to  the  shade-trees. 

In  the  idimWy  Noduidcs,  or  "owlet-moths,"  we  have  a  large 
number  of  species,  and  among  them  many  that  are  troublesome 
to  the  agriculturist.  The  moths  are,  as  a  rule,  sombre  gray  or 
brown,  expanding  when  the  wings  are  spread  between  one  and 
three  inches,  averaging  perhaps  an  inch  and  a  half  in  the  majority 
of  cases.     The  fore-wings  are  comparatively  narrow,  rather  short 


Fig.  32^v 


IMC.  315. 


Kij;.  2Qv.  pupa  of  dypsy  niolli.  Fit;s.  315,  316,  317,  larva,  cocoon,  ami  male  moth 
oi  Snicai  ia  iikhi,  llic  silk-worm.  I''ijj.  31S,  motli,  and  Fig.  323,  larva  oi  Aciunycta 
americaita. 


THE    INSECT    WORLD. 


289 


and  stout,  crossed  b}-  a  series  of  more  or  less  marked  crenulated 
or  wavy  lines,  and  with  two  usually  darker  or  paler  spots  in  the 
discal  part  of  the  wing.  Of  these,  that  nearest  to  tlie  base  of 
the  wing  is  round  or  nearly  so,  and  is  called  the  orbicular  ;  the 
other  and  larger,  nearest  to  the  outer  part  of  the  wing,  is  kidney- 


FiG.  322. 


x^-^'^r^^^^   ..    or 


Wing  of  an  owlet-moth,  with  all  the  markings  defined  and  named. — Right  wings: 
b,  hasal  line;  t.a.,  transverse  anterior  line;  m.,  median  line  or  shade;  t.p.,  transverse 
posterior  line;  si.,  sub-terminal  line;  t.,  terminal  line;  sm.,  sub-median  vein;  apex 
of  hind  wing:  o.;«.',  outer  margin  ;?.>«.',  inner  margin.  Left  wings  :  6. rf.,  basal  dash  ; 
cL,  claviform  ;  or.,  orbicular  spot ;  len.,  reniform  spot ;  ap.,  apical  spot ;  cm.,  costal  mar- 
gin ;  o.tn.,  outer  margin;  /.;«.,  inner  margin;  h.a.,  hind  angle;  d.s.,  discal  spot;  e.l., 
exterior  line  ;  an.,  anal  angle. 

shaped,  or  narrow-ovate,  and  is  called  the  reniform.  These 
terms  are  frequently  used  in  economic  literature,  and  the  spots 
are  in  many  cases  characteristic.  Taken  as  a  whole,  the  species 
of  the  Noctuid  family  are  very  much  alike,  and  no  attempt  will 
be  made  here  to  distinguish  them,  except  in  the  most  superficial 
manner.  The  hind  wings  are  usually  without  markings,  and 
when  at  rest  are  concealed  by  the  fore-wings,  which  lie  overlap- 
ping and  covering  them,  either  flat  on  the  back  or  roof-like,  a 
little  oblique.  In  the  early  part  of  the  series  we  have  a  number 
of  species  with  hairy  caterpillars  that  sometimes  feed  on  shade- 
trees.  We  occasionally  find  a  rather  large  yellow  caterpillar, 
densely  clothed  with  soft  yellowish  hairs  and  interspersed  here 
and  there  a  pencil  of  much  longer,  black  hair.  This  is  the  cater- 
pillar oi  Acronyda  ainericana,   one  of  the  "dagger-moths,"  so 

19 


290 


AA^   ECO  NO  AUG  ENTOMOLOGY. 


called  from  the  fact  that  on  the  fore-wings  there  are  a  number  of 
short  black  streaks  crossing  the  transverse  lines  in  such  a  way 
that  the  marks  have  a  remote  resemblance  to  a  dagger,  or  to  the 
Greek  letter/^/,  i<.  They  are  all  of  some  shade  of  gray,  varying 
from  very  light  ashen  or  nearly  white  to  almost  black  ;  but  none 
of  them  are  seriously  injurious. 

The  more  typical  Noctuids  are  rarely  seen  during  the  day. 
They  hide  under  bark  or  stones,  in  out-houses,  or  wherever  they 
can  find  shelter.  Occasionally  they  sit  brazenly  upon  the  trunks 
of  trees  or  branches,  or  openly  upon  stones,  their  colors  and 
markings  blending  so  perfectly  with  their  surroundings  that  they 
are  invisible,  except  to  the  trained  eye  ;  but  at  night  they  are  active 
and  fly  readily,  many  of  the  species  being  attracted  to  light,  and 
nearly  all  of  them  to  sweets  :  for  these  insects  are  furnished  with  a 
well-developed  tongue  and  require  food.  When  the  moths  are 
examined  in  the  dark,  their  eyes  are  seen  to  glow  with  a  deep 
phosphorescence  that  is  quite  startling  at  first  sight.  The  ento- 
mologist makes  use  of  their  sweet  tooth  by  what  is  known  as 
' '  baiting  "  or  "  sugaring, ' '  placing  a  mixture  of  molasses,  beer, 
and  rum  in  patches  upon  trees,  fence-posts,  or  even  stones,  and 
visiting  them  after  dark  with  a  lantern.  The  moths  are  often 
attracted  in  great  numbers  to  these  lures,  and  many  species  not 
otherwise  obtainable  are  thus  added  to  our  collections.  Many  of 
their  caterpillars  are  known  as  "cut- worms,"  and  when  full- 
grown  average  from  an  inch  to  an  inch  and  a  half,  sometimes 
reaching,  but  rarely  exceeding,  two  inches  in  length.  They  are 
naked,  obscurely  colored,  usually  varying  from  dirty  gray  to 
dirty  yellow-brown,  generally  wilh  feebly-marked  longitudinal 
lines,  and  rarely  with  well-marked  black  spots.  They  hide 
during  the  day  a  little  below  the  surface  of  the  ground  at  the 
base  of  the  plants  upon  which  they  feed,  and  during  the  night 
come  out  to  feed  upon  whatever  vegetation  they  can  find.  Nor- 
mally, the  female  moth  lays  her  eggs  in  grass  land  after  mid- 
summer, but  sometimes  weedy  fields  are  selected,  or  partly 
overgrown  orchards,  or,  in  fact,  any  location  with  a  sufficient 
quantity  of  low  vegetation  to  support  the  caterpillars.  They  are 
rarely  laid  directly  on  or  in  the  ground,  but  may  be  deposited  on 
trees,  stones,  or  leaves.  When  the  larvae  hatch,  late  in  summer 
or  early  in  fall,  they  feed   upon  whatever  vegetation   is  in  the 


Fir..  331. 


Cut-worms  and  owlet-motlis. — Fig.  324,  Agrotis  ypsilon  and  its  larva,  the  "greasy 
cut-worm."  Fig.  325,  larva  oi  Noctua  clandestina,  the  clandestine  cut-worm.  Fig.  326, 
Peridroma  saxicia.  Fig.  327,  eggs  of  the  same,  a  single  example  enlarged  at  a.  Fig. 
328,  its  larva,  the  variegated  cut-worm.  Fig.  329,  Carneades  tnessoria  and  its  larva,  the 
dark-sided  cut-worm.  Fig.  330,  the  climbing  cut-worm,  larva  of  Carneades  scandens. 
Fig.  331,  Hadena  dcvaitalrix  and  its  larva,  the  glassy  cut-worm. 

291 


292 


AN  ECONOMIC   ENTOMOLOGY. 


fields,  being  by  no  means  nice  in  their  choice,  and  only  requiring 
that  it  be  juicy  and  that  there  be  plenty  of  it.  They  become 
about  half-grown  before  winter  sets  in,  and  hibernate  among  the 
roots  of  the  plants  upon  which  they  have  been  feeding,  or  under 
stones,  logs,  or  other  cover.  In  this  condition  they  remain  until 
the  spring  following,  and  then  manifest  quite  a  variety  of  habits. 
In  orchards  some  of  the  species  develop  a  climbing  tendency, 
and  make  their  way  upon  trees  or  shrubs  to  cut  off  the  young- 
shoots  and  buds.  These  have  been  termed  ' '  climbing  cut- 
worms," but  as  a  matter  of  fact  a  number  of  species  develop 
this  habit  when  the  larvse  are  in  the  proper  location.  Where 
there  is  an  abundance  of  low  plants,  these  are  eaten  off  at  about 
the  surface  of  the  ground,  and  the  cut-worms  fill  themselves 
until  they  seem  almost  ready  to  burst  with  the  juicy  tissue. 
Where  sod  land  has  become  badly  infested  by  them,  and  is 
ploughed  and  planted  in  spring,  very  frequently  everything  is 
eaten  off  as  fast  as  it  shows  above  the  surface.  In  some  cases, 
where  they  are  very  numerous,  it  is  absolutely  impossible  to 
obtain  a  stand  of  corn,  and  the  crop  must  be  abandoned  in  favor 
of  some  other  which  the  insects  do  not  attack,  although  this 
apparent  exemption  is  frequently  due  to  the  fact  that  the  insects 
have  wandered  off,  or  have  become  full-grown  and  changed  to 
pupae.  This  change  usually  occurs  some  time  during  the  latter 
part  of  June,  or  in  July,  and  little  complaint  of  injury  from  cut- 
worms is  heard  after  that  period.  The  moths  do  not  make  their 
appearance  until  late  in  August  or  September,  and  lay  their  eggs 
during  the  latter  month.  Some  species  are  double-brooded,  and 
may  be  found  even  later  than  this,  until  November  or  even 
December.  This,  be  it  understood,  is  only  a  very  generalized 
history  of  one  group,  and  is  not  intended  to  apply  even  to  all  of 
the  genera  whose  larvae  are  cut-worms  ;  but  for  all  practical  pur- 
poses the  injurious  species  may  be  assumed  to  have  habits 
similar  to  those  just  described.  The  reason  cut-worms  are  so 
injurious  is  that  the  abundance  of  plants  in  an  overgrown  field 
where  the  eggs  are  laid  is  replaced  by  a  very  small  quantity  set 
out  by  the  farmer  for  his  purposes.  The  result  is  that  the  cut- 
worms, comparatively  moderate  in  number  in  the  first  place, 
become  exceedingly  plentiful,  and  destroy  the  cultivated  plants 
about  as  fast  as  they  make  their  appearance  or  are  set  out.     In 


THE    INSECT   WORLD.  293 

regions  where  cut-worms  art-  known  t(j  be  troublesome  it  is  a 
good  plan  to  fall-plough  sod-land  as  early  in  the  season  as  conven- 
ient. This  will  avoid  egg-laying  by  the  late  moths,  and  cater- 
pillars that  have  already  hatched  will  be  compelled  to  make  their 
way  to  points  where  food  is  more  plentiful,  leaving  the  ploughed 
field  free.  It  is  a  good  plan  also  to  put  on  at  this  time  all  the 
potash  that  is  to  be  used  on  the  crop  in  the  form  of  kainit. 
The  insects  do  not  like  this  material  on  account  ot  the  chloride 
it  contains,  and  many  of  them  will  be  killed,  while  most  of  the 
others  will  be  driven  off.  The  potash  is  not  lost,  but  will  be 
as  effective  as  if  applied  the  season  following.  The  field  can  be 
treated  in  spring  as  needed  by  the  special  crop,  and  will  then  be 
practically  free  from  cut  worms.  If  this  method  is  not  feasible 
for  any  reason,  the  cut- worms  can  be  trapped  by  spreading  on 
the  surface  of  the  ground,  after  it  has  been  prepared,  little  heaps 
of  poisoned  vegetation, — for  instance,  clover;  but  any  succulent 
plant  will  answer  the  purpose  as  well.  The  best  way  is  to  thor- 
oughly spray  a  patch  of  clover  or  other  vegetation  with  one  of 
the  arsenites,  one  pound  to  fifty  gallons  of  water,  then  mow  it 
close  to  the  ground,  and  spread  in  little  heaps  all  over  the  field. 
The  cut-worms,  finding  nothing  else  to  feed  upon,  will  eat  this 
poisonous  bait,  and  long  before  the  corn  or  potatoes  come  up  the 
field  will  be  entirely  cleared.  On  plants  like  sweet  potatoes, 
cabbages,  or  tomatoes,  that  are  set  out,  protection  can  be  secured 
by  putting  at  the  base  of  each  plant  a  tablespoonful  of  poisoned 
bran,  using  bran  at  the  rate  of  fifty  pounds  to  one  pound  of 
Paris  green.  This  should  be  thoroughly  mixed  dry,  then  water, 
just  a  little  sweetened  with  sugar,  should  be  added  until  the 
whole  is  thoroughly  wet  but  not  sloppy.  This  mixture  is  ex- 
ceedingly attractive  to  cut-worms,  being  preferred  to  plants  in 
all  the  instances  that  have  come  under  my  notice.  It  will  take 
about  ten  pounds  to  an  acre  of  potatoes  as  ordinarily  planted, 
and  perfect  protection  can  thus  be  secured.  For  one  or  two 
nights,  perhaps,  a  few  plants  may  be  cut,  but  after  that,  except 
in  rare  instances,  no  further  trace  of  the  insects  will  be  no- 
ticed. As  against  the  climbing  cut-worms  a  band  of  gas-tar 
or  coal-tar  will  in  most  cases  afTord  protection,  especially  if 
reinforced  by  a  little  mass  of  the  poisoned  bran  at  the  base  of 
each  tree.      A  broad  layer  of  fluffy  cotton  batting,    tied  at  the 


294 


AN   ECONOMIC   ENTOMOLOGY. 


bottom  and  folded  over  to  form  a  cone,  is  a^  good  substitute  for 
the  tar. 

Further  on  in  the  family  we  have  a  series  of  species  which, 
with  similar  habits  in  the  adult,  have  quite  different  larval  char- 
acteristics. The  moths  themselves  are  different  in  appearance, 
becoming  white  or  yellowish,  without  obvious  markings,  except 
irregular  streak  ings  on  the  veins  and  a  series  of  more  or  less 
marked  black  dots.  These  are  usually  members  of  the  genus 
Leucania,  and  the  caterpillars  have  been  called  in  general  "  army- 
worms,"  though  to  only  one  of  the  species  can  this  term  be  prop- 
erly applied.  The  "army-worm,"  Leucania  unipiincta,  has  the 
fore-wings  of  a  rather  even,  dull-reddish  fawn,  powdered  with 
fine  black  speckles,  some  of  which  form  a  transverse  row  of  dots 

on  the  veins  beyond 
P'iG.  iv'.  the  middle.     There 

is  also  a  fine,  ob- 
1  i  q  u  e,  blackish 
streak  just  below 
the  apex,  and  at  the 
end  of  the  median 
vein  is  a  small  white 
dot,  which  gives 
the  wing  a  rather 
characteristic  ap- 
pearance and  the 
insect  its  specific  name  ^lnip^lncta.  The  moths  fly  at  night,  and 
are  attracted  to  both  light  and  sugar,  forming  in  some  seasons 
the  most  common  of  all  the  insects  taken  by  the  collector.  The 
eggs  are  laid  on  the  leaves  or  stems  of  grasses,  using  that  term 
in  its  widest  sense,  and  usually  concealed.  The  moths  favor 
rank  vegetation,  and  the  caterpillars,  when  they  hatch,  attack 
whatever  is  nearest  at  hand.  When  full-grown  they  are  from 
one  and  a  half  to  two  inc'ies  in  length,  striped  with  yellowish  on 
a  dark-gray  ground.  The  head  is  yellow,  with  fine  dark  lines, 
and  the  insect  is  easily  recognized  when  it  appears  in  numbers. 
In  ordinary  seasons,  though  the  larvae  may  be  quite  abundant, 
they  are  little  noticed  and  do  no  particular  injury  ;  but  sometimes, 
by  a  combination  of  circumstances,  the  number  of  eggs  deposited 
early  becomes  very  great  and  the  resulting  army  of  larvae  so 


Moth  of  army-worm,  Leucania  unipuncta,  at  a;  tip  of  ab- 
domen of  female  at  b ;   c,  d,  e,  structural  details. 


THE    IXSECT    WORLD. 


295 


Fig. 


3.^,V 


The  armv-worm. 


lare:e  that  they  make  havoc  where  they  hatch.  In  thi.s  stage  they 
are  noticed  in  wlieat  where  it  is  heaviest,  and  thence  the  cater- 
pillars spread  in  every  direction.  They  soon  become  full-grown, 
go  a  short  distance  underground  to  change 
to  mahoganv-brown  pupie  about  three-ft)urths 
of  an  inch  in  length,  and  shortly  thereafter 
the  moths  appear.  They  mate  at  once  and 
lay  another  batch  of  eggs,  from  which  we 
have  about  midsummer  a  second  army  much 
larger  than  the  first.  These  soon  eat  every- 
thing on  the  ground  first  occupied  by  them, 
and  are  then  forced  by  hunger  to  begin  those 
marches  which  have  given  them  their  com- 
mon name,  "army-worm."  It  is  an  inter- 
esting, though  to  a  farmer  not  a  pleasant, 
sight  to  see  the  march  of  these  insects  from 
a  stripped  field  to  one  that  is  still  green  and 
flourishing,  and  to  note  how  quickly  every- 
thing becomes  covered  and  disappears,  a  sin- 
gle day  sufficing  to  clear  a  large  plot  of  every  trace  of  vegetation. 
When  full-grown  these  larvae  in  turn  go  underground,  and  now 
there  is  a  divergence  in  development.  Some  of  the  pupie  remain 
unchanged  all  winter  ;  some  of  them  produce  moths,  and  of 
these  some  will  go  into  winter-quarters  and  hibernate,  while 
others  mate  and  lay  eggs  for  a  late  brood  of  caterpillars,  which 
becomes  only  partially  grown.  The  insects  may,  therefore, 
winter  in  either  the  larval,  pupal,  or  adult  condition,  though  it  is 
probable  that  the  pupa  stands  the  best  chance  of  sur\iving.  At 
all  events,  this  explains  how  it  is  that  caterpillars  of  all  sizes  may 
be  found  at  all  times,  and  that  during  the  entire  season  moths 
may  be  found.  In  my  own  experience,  there  has  not  been  a 
week  in  the  collecting  year  when  I  have  not  taken  this  insect, 
while  seeking  better  species.  The  remedies  to  be  adopted  are 
almost  entirely  mechanical.  Where  the  larvae  are  noticed  at  the 
first  start  in  grain-fields  or  grass  lands,  the  patches  infested  by 
them  should  be  at  once  cut  down  and  utterly  destroyed  by 
fire,  and  with  them,  of  course,  the  larvae.  The  work  must  be 
done  thoroughly,  because  otherwise  the  caterpillars  will  simply 
crawl  to  adjacent  plots,  and  the  labor  is  wasted.     The  thorough 


2C)6  AN  ECONOMIC  ENTOMOLOGY. 

application  of  an  ar.  enical  spray  in  the  infested  patch  and  imme- 
diately surrounding  it  is  beneficial  in  some  cases,  but  there  is  the 
practical  difficulty  that  grasses  do  not  hold  a  water  spray  easily. 
Using  soapsuds  instead  of  pure  water  will  overcome  this,  how- 
ever. If  the  insects  become  abundant  enough  to  start  on  a 
march,  a  narrow  strip  can  be  ploughed  in  its  line,  harrowed  and 
rolled,  and  then  the  roller  can  be  kept  going,  crushing  the  insects 
as  they  come  upon  it.  Or  a  very  strong  kerosene  emulsion  may 
be  sprayed  upon  the  caterpillars  as  they  advance,  and  upon  the 
fields  that  they  are  leaving.  There  will  be  no  vegetation  that 
need  be  considered,  and  therefore  the  mixture  need  be  diluted 
five  times  only,  which  will  be  effective  even  against  the  nearly 
full-grown  larvae.  It  would  seem  that  following  one  army  of 
caterpillars  we  would  have  next  year  a  still  more  destructive  in- 
vasion, but  such  is  not  usually  the  case.  Fungus  and  other  dis- 
eases appear  and  decimate  their  ranks,  their  enemies  increase 
rapidly  after  the  first  large  brood,  and  the  result  is  that  normal 
numbers  only  survive,  unless  the  conditions  which  favor  their 
increase  one  year  continue  also  the  next.  As  the  land  becomes 
more  cut  up  and  cultivated,  the  danger  from  this  insect  is 
correspondingly  lessened,  and  where  a  reasonable  amount  of 
promptness  is  displaycjd  on  its  first  appearance  no  wide-spread 
injury  need  be  anticipated.  Everything  depends  upon  the 
promptness  and  thoroughness  with  which  early  measures  are 
adopted  and  carried  out,  and  all  delays  will  prove  costly. 

A  near  relative  of  the  true  "  army-worm"  is  the  insect  known 
as  the  "wheat-head  army-worm,"  Leiicania  albilinea.  This  is 
a  rather  brighter  larva,  also  striped  with  yellow,  never  becoming 
quite  as  large  as  its  ally,  and  peculiar  in  the  habit  of  eating  the 
grain  or  seed  of  wheat,  rye,  and  other  grasses.  There  are  two 
broods  of  this  insect  also  during  the  year,  but  that  which  does 
the  injury  makes  its  appearance  in  the  nearly  full-grown  larval 
condition  just  when  the  grain  is  ready  to  ripen.  At  this  time, 
when  sufficiently  numerous,  their  injuries  to  the  crop  are  severe, 
because  a  single  caterpillar  may  in  a  few  minutes  practically  de- 
stroy the  value  of  an  entire  head  of  wheat.  The  ears  become 
ragged  and  the  surface  of  the  soil  becomes  littered  like  a  barn 
floor  after  threshing.  The  moths  from  which  these  insects  are 
derived  expand  a  little  more  than  an  inch,  and  are  of  a  rather 


rilE    INSECT   WORLD. 


297 


pale  clay-yellow,  with  a  narrow,  silver-gray  margin  to  the  outer 
edge  of  the  fore-wing.  There  is  also  a  dusky  stripe  through 
its  centre,  surmounted  by  a  white 
streak,  which  gives  the  specihc 
name  a/bilinea,  or  "white  lined." 
Practical  measures  against  this  in- 
sect are  difficult.  Where  the  stage 
of  the  grain  warrants  it  in  any  way, 
the  best  thing  is  to  cut  it  at  once. 
This  will  save  further  injury,  and  the 
insects  will  distribute  themselves  to 
localities  where  their  mischief  will 
not  count  so  heavily.  As  with  the 
previous  species,  increase  is  depend- 
ent upon  conditions  which  we  do 
not  entirely  understand,  and  here 
also  the  parasites  ordinarily  obtain 
control  before  the  year  is  out. 

The  wandering  habit  is  somewhat 
developed  in  this  species  as  well, 
and  frequently  they  start  in  grass 
lands  and  emigrate  to  adjacent 
grain-fields  when  the  wheat-heads 
are  well  advanced. 

An  insect  somewhat  similar  in 
appearance  in  the  caterpillar  stage  is 
the  "fall  army- worm,"  Laphygma 
fnigipcrda.  It  is  smaller,  however, 
the  head  dark  with  a  prominent, 
white,  V-mark,  while  the  lines  are 
different  and  the  body  is  covered 
with  rather  well  marked  black  tuber- 
cles, giving  rise  to  short,  stiff,  black 
hair.  The  creature  is  a  general 
feeder,  and  appears  in  greatest  num- 
bers late  in  the  season  in  fields  of 
dense  vegetation  of  almost  any  kind 
not  differ  much  from  the  species  already  described,  and,  like 
them,  it  goes  underground  to  pupate.     There  are  always  two, 


The  wheat-heaii  army-worm. — 
a,  a,  eating  out  a  liead  of  grain  ;  b, 
eggs  under  a  leaf  sheath  ;  enlarged 
at  c,  d ;  the  moth,  Leiicania  albilinea, 
surmounting  all. 

In  general  habits  it  does 


298  yljV  ECONOAIIC   ENTOMOLOGY. 

and  sometimes  three  or  more  broods  in  the  course  of  the  year, 
and  in  favorable  seasons  these  become  successively  more  numer- 
ous, so  that  the  fall  brood  proves  the  most  troublesome.  These 
favorable'  seasons,  however,  do  not  often  occur,  particularly  in 
the  Eastern  United  States,  and  here  climatic  influences  or  other 
natural  conditions  reach  the  insects  during  the  winter,  so  that  in 
the  spring  following  only  a  normal  number  survive.  Cultivating 
land  in  crops  which  admit  of  fall  ploughing  is  best  adapted  to 


Fig.  335. 


Fig.  336. 


The  fall  army-worm.— i,  its 
head  ;  c,  d,  its  body  segments 
enlarged. 


Laphygttia  fnigiperda    and 
variations. 


avoid  injury,  and  a  frequent  rotation  will  prevent  them  from  be- 
coming numerous  enough  to  be  destructive  at  any  time.  The 
arsenites  can  be  employed,  of  course,  for  the  protection  of  crops 
that  admit  of  being  sprayed.  Wheat-fields  badly  infested  in  fall 
are  not  necessarily  ruined  or  even  much  injured,  because  wheat 
will  stand  cutting  down  almost  to  the  ground  during  the  latter 
part  of  the  season,  and  will  yet  come  up  vigorous  and  in  good 
condition  the  spring  following.  The  moth  that  produces  this 
caterpillar  is  a  modest,  gray  creature,  expanding  hardly  more 
than  an  inch,  and  the  hind  wings  are  pure  white  and  semi-trans- 
parent. It  is  a  variable  species,  and  ranges  from  an  almost  uni- 
form gray  to  forms  in  which  there  is  a  considerable  admixture  of 
bluish  white,  the  ordinary  lines  and  spots  of  the  owlet-moths 
being  also  well  marked. 


TIIF.    IXSECT   ]VORLD. 


299 


We  sometimes  find  boring-  in  the  stems  of  wheat,  corn,  pota- 
toes, and  a  great  variety  of  other  plants  a  yellowish-white  cater- 
pillar with  nither  prominent  black  spots,  luniislud  with  little 
soft  hairs  and  with  a  black  head.  This  is  the  larva  of  another 
Noctuid  moth,  the  .Ichatodes  zcce.  It  sometimes  does  consid- 
erable, though  usually  temporary,  injury  to  the  infested  plants, 
and  is  kept  in  check,  as  a  rule,  by  its  natural  limitations.  The 
moth  which  produces  this  caterpillar  is  broader  winged  than  the 
species  previously  mentioned,  and  the  primaries  are  of  a  deep, 
somewhat  mottled,  red-brown.  The  outer  margin  is  rusty  red, 
especially  towards  the  tip  of  the  wing,  and  none  of  the  other 
markings  are  well  defined.  The  species  has  not,  in  my  experi- 
ence, appeared  in  numbers  large  enough  to  make  it  necessary  to 
adopt  remedial  meas- 
ures, and  this  is  fortu- 
nate, because  from  its 
method  of  feeding  it  is 
somewhat  beyond  our 
reach. 

Occasionally  we  note 
upon  grape-vines  a 
smooth,  greenish  cat- 
erpillar with  broken, 
rather  inconspicuous, 
lateral  lines.  It  attains  a 
length  of  from  one  and 
one-half  to  two  inches, 
and  differs  from  the 
other  greenish  cater- 
pillars of  the  vine  by  lacking  all  trace  of  either  horn  or  eye-spot 
on  the  last  segment.  It  pupates  a  little  below  the  surface,  and  in 
due  time  appears  as  a  moth  which  is  distinctly  flattened,  has  the 
fore-wings  of  a  mottled,  dull,  smoky  brown,  and  the  hind  wings 
of  a  dull  coppery  hue.  It  is  the  Pyrophila  pyrainidoides,  and 
may  be  occasionally  found  during  the  day  hiding  in  crevices,  or 
under  bark,  for  which  its  flattened  body  adapts  it  unusually  well. 
At  night  it  is  attracted  to  light,  and  occasionally  becomes  rather 
common,  though  rarely  abundant  enough  to  need  remedial 
measures.     When  it  does  occur  in  numbers  it  is  easily  controlled 


Pyrophila  pyramidoides  and  its  larva. 


300 


AjV  econoafic  entomology. 


by  the  application  of  a  stomach  poison,  the  caterpillar  succumb- 
ing readily  to  any  of  those  in  ordinary  use. 

There  is  a  series  of  decidedly  depressed  or  flattened  moths  with 
narrow,  long  fore-wings,  broad  hind  wings,  a  somewhat  retracted 
head  clothed  with  stitf,  projecting  vestiture,  and  a  neat  little  tuft 
on  the  anterior  part  of  the  thoracic  collar.  These  belong  to  the 
genus  Xylina,  or  its  near  allies,  and  they  appear  late  in  fall,  to 
hibernate  as  adults.  In  spring  they  reappear  as  soon  as  the 
weather  becomes  in  the  least  warm,  and  moths  of  this  kind  are 

Fig.  338. 


Xyliiia  antc-nnata :  a,  its  larva  in  peach  ;  b,  adult  motli. 


often  found  in  maple  groves  while  sugaring  is  going  on.  Some- 
times sap-pails  are  found  in  the  morning  with  the  surface  of  the 
liquid  completely  covered  with  these  insects,  which,  taken  as  a 
whole,  are  northern,  though  some  extend  south  and  southwest, 
and  even  to  the  Pacific  coast.  One  of  the  most  common  is  the 
X.  antennata,  the  caterpillar  of  which  has  been  described  by 
Riley  as  boring  into  fruits  ;  but  it  is  a  rare  species,  comparatively, 
and  no  marked  injury  is  ever  done. 

Now  we  reach  a  group  of  moths  in  which  the  caterpillars 
usually  lack  one  pair  of  the  false  or  abdominal  legs,  and  for  this 
reason  are  known  as  "  semi-loopers,"  having  somewhat  the 
methods  of  motion  found  in  the  "span-worm,"  but  not  to  so 
marked  an  extent.  Of  this  series  we  have  several  more  or  less 
troublesome  species,  and  the  most  important  are  the  "cotton- 
worms"  belonging  to  the  genera  Anomis  and  Alejja,  all  of  them 
feeding  upon  the  leaves.  The  larvae  are  similar  in  appearance, 
green,  more  or  less  narrowly  banded  at  the  sides,  and  spotted. 


THE    IXSECT    IVOKIJh 


301 


K-   339- 


The  "  cotton-worm"  is  the  larva  of  Aletia  argillacea,  about  which 
many  volumes  have  been  written,  and  whose  life  history  has 
been  thoroughly  investigated  under  the  direction  of  the  United 
States  Entomological  Commission 
and  the  entomologists  of  the  United 
States  Dei)artment  of  Agriculture. 
To  one  especially  interested  in  this 
insect  these  elaborate  reports  will  hr 
useful  and  must  be  consulted.  It 
will  suffice  here  to  say  that  the 
caterpillars  pupate  in  a  loose  co- 
coon spun  on  the  leaves  of  the 
plants,  and  from  the  dark-brown 
[)upa  comes  a  dull,  tawny  or  clay- 
colored  moth,  with  intlistinct,  dark, 
wavy,  transverse  lines,  and  a  rather 
prominent  leaden-white  spot,  more 
or  less  margined  with  t^lack,  near 
the  middle  of  the  fore  wings.  There 
are  several  broods  in  the  course  of 
the  year,  but  only  the  later  ones  be- 
come seriously  injurious,  the  plant 
then  being  sometimes  entirely  de- 
foliated. A  curious  feature  is  that 
the  insects  probably  do  not  spend 
the  winter  in  our  territory,  but  adults  immigrate  each  year  from 
more  southern  regions.  The  migrating  habit  is  marked  in  the 
later  broods  maturing  on  cotton  in  our  country,  and  the  moths 
have  been  often  seen  in  great  numbers  as  far  north  as  Canada. 
As  the  wings  are  closely  scaled,  they  do  not  readily  show  the 
wear  and  tear  of  long  flight,  and  specimens  have  been  taken 
in  the  for  north  as  fresh  and  bright  as  if  hatched  there.  It  is 
})Ossible  that  under  favorable  circumstances  the  caterpillars  may 
support  themselves  on  plants  other  than  the  cotton,  but  we 
have  no  positive  information  of  their  having  done  so.  Of  late 
years  the  insects  are  much  less  injurious  than  in  times  past, 
largely  as  the  result  of  a  diversified  agriculture,  which  has  made 
it  less  easy  for  them  to  increase  in  abnormal  numbers.  Planters 
have  also  learnt  that  a  prompt  application  of  the  arsenites  when 


Cotton-worms,      from 
above. 


side      and 


302 


AN   ECONOMIC   ENTOMOLOGY. 


the  larvae  first  appear  is  apt  to  lessen  subsequent  injury,  if  it  does 
not  prevent  it  entirely.  The  method  of  application  now  adopted 
is  exceedingly  simple,  consisting  of  a  moderately  stout,  rather 
elastic,  pole,  to  the  ends  of  which  are  attached  sacks  of  a  coarse 
ducking  material  containing  Paris  green.  This  pole  is  carried 
by  a  man  on  muleback,  who  rides  between  the  rows,  continually 
jarring  it  so  that  the  poison  sifts  through  the  sacks  upon  the 

Fig.  340. 


Aletia  aigillacea  at  rest  and  with  wings  expanded. 

plants.  It  has  been  found  that  undiluted  Paris  green  used  in 
this  way  does  not  injure  the  foliage,  while  it  is  absolutely  effective 
as  against  the  larvae.  Sometimes  the  pole  is  made  long  enough 
to  hold  four  sacks,  so  that  four  rows  are  dusted  at  one  time.  This 
is  exceedingly  simple  and  practical,  and  has  the  advantage  of  re- 
quiring no  expensive  outfit. 

We  have  belonging  to  this  series  of  semi-loopers  a  number  of 
moths  belonging  to  the  genus  Plusia,  and  most  of  these  have 
somewhere  in  the  middle  of  the  fore- wing  a  dash,  line,  circlet,  or 
other  marking  of  silver  or  gold.  Sometimes  the  entire  surface  is 
metallic  or  golden,  and  the  species,  as  a  whole,  are  very  hand- 
some, with  the  ground  color  in  most  cases  velvety  gray  or 
brown.  Bright  colors  or  contrasting  markings  are  rare.  Several 
of  the  larvae  attack  cultivated  plants,  but  none  as  frequently  as 
that  of  P.  brassicce,  the  cabbage  Plusia.  The  caterpillar  is 
green,  with  rather  indistinct  lateral  lines,  and  is  readily  sepa- 
rated from  the  butterfly  larva  of  Pieris  rapes,  because  it  lacks 
one  pair  of  abdominal  legs  and  is  not  at  all  velvety  in  appear- 
ance. Its  fashion  of  "  humping  itself"  also  separates  it  from  the 
other  larva,  which  always  rests  fully  extended.  This  may  be 
dealt  with  as  has  been  already  recommended  foi  the  other  ' '  cab- 


THE    INSECT    WORf.n. 


bage-worm,"  and  as  they  infest  the  plants  at  about  tliesame  time 
in  midsummer,  one  apphcation  of  Paris  green  or  London  purple 
will  answer  for  both  insects. 


?^VT~^^^ 


The  cabbage  Plusia,  /-".  btassiciC.—a,  larva  ;  b,  pupa  in  its  thin  cocoon  ; 
c,  male  adult. 


Another  series  of  usually  bright-colored,  active  moths  that  fly 
during  the  day,  sometimes  in  the  hottest  sunshine,  is  the  Helio- 
thini,  which  are  usually  white  or  yellow  in  color,  and  not  infre- 
quently have  a  glossy  or  metallic  lustre.  Taken  altogether,  the 
species  are  not  common,  and  are  much  more  abundant  both  in 
specimens  and  species  in  the  West  and  Southwest.  But  we  have 
one  form,  abundant  throughout  the  Eastern  United  States,  which 
is  at  once  the  langest,  least  conspicuous,  and  most  destructive  of 
those  belonging  here,  yielding  little,  in  the  injury  it  does,  to  any 
other  Noctuid.  It  is  the  Heliothis  armiger,  whose  caterpillar  is 
locally  known  as  the  "  boll-worm"  in  the  South,  where  it  bores 
into  cotton-bolls  ;  the  "  corn-worm"  in  the  North,  from  its  habit 
of  eating  into  ears  of  corn,  and  the  "tomato-worm"  in  some  of 
the  Eastern  States,  from  its  habit  of  boring  into  tomatoes  during 
the  early  part  of  the  season.  The  species  is  one  of  the  most 
difficult  to  deal  with  directly,  from  its  habit  of  feeding  concealed 
in  such  a  way  that  in  most  cases  the  application  of  arsenites  is 
a  practical  impossibihty.     It  has  been  found  by  experience  that 


304 


AjV  economic  extomologv. 


corn  is  the  favorite  food,  and  they  will  attack  it  in  preference  to 
everything  else.  This  preference  is  utilized  by  planting  corn  in 
cotton-fields  in  such  a  way  that  the  ears  are  in  attractive  condi- 
tion at  the  time  when  the  moths  would  otherwise  oviposit  in  the 
bolls.  Before  the  caterpillars  come  to  maturity  they  can  be  de- 
stroyed by  hand  in  the  ears,  or  the  corn  can  be  cut  and  fed  to 
stock,  together  with  the  caterpillars.     This  is  really  the  most 


Fig.  342. 


Heliothis  armiger  in  all  stages.— a,  b,  egg,  enlarged ;   c,  larva ;    rf,  pupa  in  its  under- 
ground cell;  e,f,  moths. 

satisfactory  way  of  dealing  with  this  insect  in  cotton- fields.  By 
providing  early  corn  for  the  early  broods  of  larvae,  and  destroying 
it  before  they  mature,  the  species  can  be  kept  down  to  harmless 
numbers  later  in  the  season.  The  adoption  of  a  more  diversified 
agriculture  will  have  a  tendency  to  lessen  injury  to  the  cotton, 
and  if  systematic  fall  ploughing  of  corn-fields  be  practised,  it 
will  soon  become  insignificant.  There  are  two  or  three  broods 
in  the  latitude  of  New  Jersey  and  even  more  southwardly,  while 
in  its  most  northern  range  a  single  brood  only  is  normal.  In 
September  or  early  October  the  caterpillars  that  mature  in  corn 
go  underground  and  change  to  pupae,  passing  the  winter  in  this 


Ftr..  ;,4;v 


Work  of  tlie  Ihivii  u(  llrliolhis  ai 


lint: r I   111  1-1  nn  an 


I  III  luliiaiucs. 


THE    INSECT    WORLD. 


305 


condition.  Early  in  spring,  if  the  ground  remains  undisturbed, 
the  moths,  which  are  of  a  dull  clay-yellow,  with  indistinct  mark- 
ings on  the  fore-wings,  and  expand  from  one  and  one-half  to  two 
inches,  make  their  appearance  and  lay  eggs  upon  such  plants  as 
they  can  find.  Early  tomatoes  are  favorites,  and,  following  them, 
peas  are  infested.  The  caterpillars  bore  at  first  into  the  stems 
of  the  tomatoes,  but  always  attack  the  fruit  as  soon  as  it  has  set. 
The  earliest  tomatoes  are  thus  frequently  ruined,  and  as  these 
usually  have  the  greatest  market  \'alue,  the  actual  money  injury 
is  out  of  all  i)roportion  to  the  quantity  of  fruit  destroyed.  Sweet 
corn  is  next  attacked,  and  the  earlier  it  is  the  more  abundant  will 
the  insects  be  found  in  it.  Last  of  all  field  corn  is  taken,  and 
this  remains  infested  until  it  becomes  hard  and  glazed,  the  cater- 
pillars being  able  to  make  their  way  through  and  feed  upon  the 
perfectly  ripe  kernel.  Fortunately,  they  are  great  cannibals,  and 
where  several  infest  a  single  ear  of  corn  they  fight  until  one  alone 
remains.  On  tomatoes  the  insects  cannot  be  satisfactorily  treated, 
except  by  picking  and  destroying  the  infested  fruit  as  soon  as  it 
is  noticed,  and  the  only  practical  means  of  keeping  them  in 
check  is  fall  ploughing  all  corn-fields.  It  has  been  found  by  ex- 
periment and  by  practical  experience  that  ploughing  in  the  fall 
and  breaking  up  the  earthen  cells  in  which  the  pupae  rest  will  in 
almost  every  instance  result  in  their  death,  and  this  process  alone 
offers  a  fair  opportunity  for  controlling  the  pest. 

There  follow  in  the  natural  series  a  great  number  of  small  spe- 
cies, some  of  them  very  bright  and  pretty,  many  with  interesting 
life  histories,  but  none  of  practical  importance  from  the  economic 
stand-point.  They  are  in  turn  followed  by  a  series  of  larger 
species  with  broad  wings  and  dull  colors,  the  secondaries  fre- 
quently crossed  with  lines  much  as  in  the  primaries.  The  cater- 
pillars are  half-loopers  in  most  cases,  and  bear  a  very  strong 
resemblance  to  the  "span-worms."  The  most  common  of  the 
species  belonging  here  are  the  clover  moths,  Drasteria  erechtea 
and  D.  crassmscula,  which  are  so  nearly  alike  that  they  have 
been  confused  in  collections,  and  we  need  not  trouble  to  separate 
them.  Both  are  broad-winged,  dirty  gray  or  brown  in  color, 
with  two  more  or  less  marked  blackish  or  brown  bands  on  the 
fore-wangs,  and  a  series  of  little  black  dots  before  the  apex.  The 
female  is  much   more  modest  in  color  than  the  male,  and  the 

20 


3o6 


AN   ECONOMIC   ENTOMOLOGY. 


black  markings  are  so  reduced  as  to  be  scarcely  visible,  except 
on  careful  inspection.  The  caterpillar,  which  is  green  and  nar- 
rowly striped,  feeds  on  clovers,  and,  while  abundant,  is  not  prac- 
tically harmful. 

Among  the  pets  of  the  lepidopterist  are  the  species  of  Catocala, 
a  series  of  large  moths  with  the  hind  wings  black,  or  yellow  and 

red     banded    with 
f*"'^-  -W-  black.     We  have  a 

great  number  of 
species,  and  while 
the  hind  wings  are 
so  prominently  col- 
ored and  marked, 
the  fore-wings  are 
mottled  gray, 
brown,  and  black. 
They  rest  exposed 
during  the  day  up- 
on the  bark  of  trees, 
entirely  invisible 
because  so  closely 
resembling  their  surroundings,  the  gaudy  hind  wings  being  com- 
pletely covered  by  the  modest  fore-wings.  While  some  of  the 
caterpillars  feed  upon  cultivated  plants,  especially  the  plum,  they 
are  never  abundant  enough  to  attract  attention. 

Last  in  the  Noctuids  we  have  the  "snout-moths,"  or  deltoids, 
the  latter  term  applied  from  the  fact  that  when  the  insects  are  at 
rest  the   outline  bears   somewhat  a  re- 
semblance to  the  Greek  letter  delta  J. 
The    species    are    recognizable   without 
much    trouble    by   the    unusually   long 
palpi,  which  in  many  cases  point  directly 
forward  and  form  a  decided  snout.     The 
only  species  that  has  occurred  in  num- 
bers justifying  the  term  injurious  is  the 
Hypena  huimili,  the  caterpillar  of  which 
— a  slender  green  creature — feeds  upon 
hops.      Within    my   experience    it   has   never   been    sufficiently 
troublesome  to  make  insecticides  necessary  ;  but  should  it  ever 


Catocala  uUronia  and  its  larva. 


Fig.  348. 


Hypena  hiimiili,  hop-vine 
moth. 


THE    INSECT   WORLD. 


307 


become  so,  there  would  be  no  trouMe  in  protectir.g  the  plants 
by  means  of  the  arsenites. 

Now  we  reach  the  family  Gcovictrida,  in  which  the  larvae  lack 
all  save  one  or  at  most  two  pair  of  false  or  abdominal  legs.  In 
moving  they  first  extend  the  body  to  its  full  length,  then  bring 
the  posterior  end  close  to  the  front  legs,  looping  the  body  in 
the  centre,  then  stretch  out  again  and  repeat  the  procedure, 
whereby  they  have  gained  the  names  ' '  span-worms, "  "  loopers, ' ' 
or  "measuring-worms,"  and,  indirectly,  the  scientific  term 
GeometridiE.  There  is  never  any  difiiculty  in  recognizing  the 
caterpillars,  and  the  moths  are  easily  known  in  most  instances  by 
their  slender  bodies,  small  heads,  and  very  broad  wings,  which 
are  also,  as  a  rule,  frail  and  thin.  The  hind  wings  are  here  orna- 
mented much  as  are  the  fore-wings,  so  that  the  lines  of  the  one 
pair  are  often  continued  across  the  other.  When  at  rest,  the  in- 
sects kecj)  the  wings  extended  and  flat,  much  as  specimens  are 
pinned  in  the  cabinet.  We  have  a  large  number  of  species,  but 
comparatively  few  of  them  become  troublesome. 

Perhaps  the  best  known  of  all  are  the  "  canker-worms,"  larvae 
of  the  species  of  Anisop- 

tayx     and      Paleacrita.  ^^^-  349- 

These  attack  a  consider- 
able variety  of  trees,  and 
are  especially  fond  of 
apple  and  pear,  which 
are  sometimes  completely 
defoliated.  They  are 
much  more  troublesome 
in  the  New  England  and 
Northern  States,  and  I 
have  often  seen,  in  Mas- 
sachusetts, orchards  com- 
pletely defoliated  by 
them.  In  New  Jersey 
and  southward  they 
rarely  become  trouble- 
some.    Here,  as  in  some 

of  the  Bombycids,  the  sexes  are  unlike,  the  males  being  wnnged, 
while   the  females   are  wingless.      The    caterpillars,   when    full- 


FiG.  350. 


Fig.  349,  Paleacrita  veinata. — a,  male  ;  b,  fe- 
male;  c,  d,  structural  details.  Fig.  3,so,  Anisop- 
teiyx-  pometaria. — a,  male ;  b,  female ;  c,  d,  e, 
structural  details. 


3o8 


y4A'   ECONOMIC  ENTOMOLOGY. 


grown,  descend  to  the  ground  to  pupate  ;  when  the  females 
emerge  they  crawl  up  the  trunks  of  the  trees,  where  they  are 
fertilized  by  the  males,  and  then  continue  their  journey  to  the 
leaves,  upon  which  they  lay  their  eggs.  This  habit  gives  us 
control  of  the  insects,  for  if  we  simply  band  the  tree  in  such  away 
as  to  prevent  either  the  female  or  the  young  caterpillars  from  as- 
cending to  the  branches,  it  will  be  protected  completely.  Unless 
the  female  can  get  upon  the  leaves,  the  eggs  are  laid  upon  the 


Fig.  .-^51. 


Fig.   352. 


Canker-worm,  larva  of  Anisoptcryx  povietatia. 
— (7,  *,  egg,  enlarged  ;  e,  patch  of  eggs  ;  r ,  rf,  body 
segments  of  _/,  larva  ;  g,  pupa  of  female. 


a,  lar\-a  of  Paleacrita  vernata ; 
f>,  an  egg,  much  enlarged  ;  c,  d, 
body  segments  of  lar\'a. 


trunk  below  any  obstruction  that  it  cannot  pass.  The  young 
larvse  will  attempt  to  get  to  the  leaves,  and  will,  if  they  find  an 
impassable  barrier,  starve  to  death.  The  best  materials,  all 
things  considered,  are  "  raupenleim,"  or  "  dendrolene,"  prefer- 
ably the  latter,  as  it  remains  viscid  for  the  full  period  during 
which  the  insects  hatch,  and  forms  a  perfect  barrier  beneath  or 
through  which  no  creature  can  crawl  and  live.  A  band  six 
inches  in  width  and  a  quarter  of  an  inch  or  more  in  thickness 
over  thick  wrapping-paper  will  prove  a  perfect  protection.  Fluffy- 
wool  or  cotton  may  also  be  employed,  and  the  former  is  the  most 
lasting,  but  less  certain  than  the  "dendrolene." 

A  near  relative  of  these  canker-worms  is  the  ' '  lime-tree  moth, 
Hybeniia  tiliaria,  which  also  attacks  a  variety  of  trees,  and  has 
at  times  been  decidedly  troublesome.  The  application  of  the 
arsenites  will  prove  a  complete  protection  in  this  case  ;  indeed,  we 
may  say  of  all  the  caterpillars  belonging  to  this  family,  including 
the  "  canker-worms,"  that  they  can  be  controlled  by  the  thor- 
ough application  of  stomach  poisons  to  the  plants  upon  which 
they  feed. 


rilE    INSECT   WORLD. 


309 


One  curious  feature  is  that  nearly  all  these  span-worms  closely 
resemble  little  tlried  twigs,  branches,  or  even  the  stems  of  the 
leaves  ujion  which  they  feed.  Many  of  them  when  at  rest  hold 
to  the  twig  by  the  hind  feet  only  and  keep  the  body  rigidly  ex- 
tended, seeming  for  all  the  world  like  a  small  process  from  the 


The  lime-tree  moth,  Hybernia  liliaria. — Larva  all  sizes  ;  winged   male  and  wingless 

female. 


plant  itself.  I  well  remember  one  occasion  when  Cymatophora 
pampiyiaria  was  excessively  abundant  on  certain  cranberry  bogs 
on  Cape  Cod.  I  saw  the  spaces  that  had  been  defoliated  and  saw 
the  edge  of  the  spaces  unaffected,  but,  look  as  I  would,  I  could 
not  at  first  see  the  caterpillars.  It  was  not  until  a  little  smoke 
was  started  over  the  edge  of  the  attacked  portion  that  larvae  were 
observed,  and  then  it  seemed  as  if  all  the  little  twigs  and  branches 
obtained  life  in  an  instant  and  started  travelling:.      The  insects  so 


3IO  AN  ECONOMIC   ENTOMOLOGY. 

closely  resembled  the  cranberry  stems  and  twigs  that  even  to  an 
entomologist  they  were  at  first  invisible. 

The  balance  of  the  Lepidoptera  are  classed  in  a  general  way  as 
"  micro,'-'  or  small,  although  as  a  matter  of  fact  many  of  them 
are  larger  than  some  of  the  "  macros."  Yet,  as  a  rule,  the  fam- 
ilies contain  small,  and  sometimes  very  small,  forms. 

At  the  head  of  this  aggregation  is  placed  the  superfamily 
Pyralididce,  which  contains  species  of  moderate  size,  varying 
greatly  in  appearance.  We  have  one  series,  the  Pyraustidcs, 
with  slender  bodies  and  rather  thinly  scaled  wings.  The  pri- 
maries are  banded,  the  secondaries  are  moderate  in  size,  never 
larger  than  the  fore-wings,  and  the  colors  are,  as  a  rule,  pale, 
usually  a  light  clay-yellow,  while  the  markings,  which  are  wavy, 
are  yellowish  brown  or  black.  The  caterpillars  in  this  series  are 
nearly  always  green,  with  pale  stripes  and  spots  ;  sometimes 
without  any  markings  at  all.  The  head  is  either  black  or  yellow, 
hard  and  shining,  and  there  is  a  hard  shield  of  the  same  color  as 
the  head  on  the  first  thoracic  segment.  Most  of  them  have  the 
abdominal  legs  crowned  with  a  complete  circlet  of  spines,  and  by 
this  character,  which  is  an  easy  one  to  see,  we  can  tell  with  al- 
most absolute  certainty  the  caterpillar  of  a  micro  from  that  of 
a  macro,  in  which  the  circlet  of  hooks  is  never  complete,  if  we 
except  the  HepialidcE  and  CossidcB,  which  will  not  confuse  us,  on 
account  of  their  great  size  and  wood-boring  habits.  The  pro- 
legs  are  complete, — that  is  to  say,  there  are  four  pairs, — and  the 


Fig.  354. 


The   pickle-molli,  Margaronia  nitida/is,  and   its  larva;    the  latter  shown  on    a  small 
cucumber  which  had  been  eaten  into  at  b. 

insects  have,  therefore,  no  appearance  of  or  relation  to  the 
loopers,  or  Geometrid(£.  Many,  perhaps  most,  of  the  caterpillars 
are  silk- spinners,  and  often  live  more  or  less  concealed  in  folded 
leaves  held  together  by  a  few  threads,  or  in  tubes  above  or  under 


THE    INSECT    WORLD. 


3" 


ground.  Occasionally  quite  large  nests  are  built,  and  the  cater- 
pillars are  more  or  less  gregarious,  or  live  together  in  colonies. 
One  of  the  injurious  species  is  Margaronia  nilidalis,  quite  a 
pretty  brown-and  yellow  insect  called  the  "pickle-moth,"  be- 
cause the  caterpillar  has  the  habit  of  feeding  on  the  cucumber, 
boring  into  and  destroying  it  when  about  half-grown.  It  is  more 
common  in  the  Western  States,  and  no  satisfactory  recommenda- 
tions for  its  control  have  yet  been  made. 

The  great  majority  of  the  caterpillars  live  upon  low  herbage 
generally,  rarely  in  numbers  sufficient  to  cause  perceptible  injury, 
and  most  of  the  species  are  classified  under  the  genus  Pyrausla. 
We  frequently  notice,  in  jjassing  through  patches  of  ferns,  that  the 
leaves,  before  they  become  entirely  unfolded,  are  spun  up  and 
held  undeveloped.  If  we  look  closely  we  find  a  typical  Pyralid 
caterpillar,  which  is  easily  observed  and  bred,  pupating  in  the 
web  itself,  while  the  resulting  moth  is  typical  of  this  genus. 

The  most  troublesome  species  is  the  "garden  web- worm," 
Loxostege  simiialis,  or,  as  it  used  to  be  called,  Eurycreon  ran- 
talis,  and  this  is  a  great  pest  on  vegetables  of  all  kinds,  seeming 
indifferent  to  the  character  of  its  food  and  spinning  its  small  web 
e\erywhere  on  the  plants. 
It  extends  over  most  of 
the  United  States,  and 
has  been  more  or  less 
injurious  in  almost  every 
section  ;  but,  like  many 
others,  it  seems  to  be 
troublesome  a  year  or 
two  and  then  escapes 
notice  for  several  years 
thereafter.  So  far  we 
have  not  been  able  to 
make  out  a  regular  peri- 
odicity, and  the  remedy  is  Paris  green  or  one  of  the  other  arse- 
nites  where  it  can  be  practically  applied.  The  insecticide  is 
sometimes  a  little  slow  to  act  because  the  insects  are  more  or 
less  sheltered,  and  it  is  only  when  they  feed  outside  their  web 
that  they  risk  being  poisoned.  In  some  cases  the  kerosene  emul- 
sion is  useful,  and  acts   more  promptly  because  of  its  ability 


Fig. 


355- 


The  "garden  web-worm,"  Loxostege  shnilalis; 
— a,  larva;  b,  c,  single  segments  of  same;  d, 
pupa;  e,  its  tip  ;  y",  moth.  ' 


312 


AN  ECONOMIC   ENTOMOLOGY. 


to  penetrate  the  webs  and   come  into  direct  contact  with   the 
larvae. 

Sometimes  insects  of  this  series  are  not  confined  to  green 
vegetation,  as  in  the  case  of  the  "clover-hay  worm,"  Asopia 
costalis,  which  attacks  the  dry  or  partially  dry  product,  webbing 

it  up  and  causing  more  or 
Fig.  356.  less  injury.     Its  near  ally, 

Pyralis  farinalis,  may  be 
found  in  barns  or  bins 
where  grain  is  carelessly 
stored,  and  the  caterpil- 
lars make  little  tubes, 
formed  partially  of  silk, 
partially  of  fragments  of 
the  grain  and  even  of  en- 
tire kernels,  upon  which 
they  feed.  Rarely,  how- 
ever, are  they  abundant 
enough  to  do  serious  in- 
jury, and  as  against  both 
cleanliness  will  go  far, 
while  bisulphide  of  carbon 
will  readily  destroy  the  larvae.  As  against  the  "clover-hay 
worm,"  nothing  is  better  than  to  feed  up  clean  from  year  to  year. 
Never  put  new  hay  upon  old,  and  if  stacked  outside,  lay  upon 
rails  so  as  to  get  ventilation  underneath.  Salting  the  first  two  or 
three  feet  has  also  been  recommended,  and  will  probably  be 
effective. 

In  the  Phycitince  there  are  many  sombre-colored  little  moths, 
usually  of  some  gray  tint,  with  rather  narrow  fore  and  broad 
hind  wings.  The  insects  rest  with  the  wings  closely  folded 
around  the  body,  the  head  a  little  elevated,  and  the  palpi  project- 
ing forward,  giving  them  rather  an  impertinent  appearance.  The 
caterpillars  are  largely  internal  feeders,  attacking  fruits  in  many 
cases,  sometimes  living  in  the  stems  of  plants,  sometimes  spin- 
ning up  among  leaves,  in  rare  cases  feeding  openly.  Occasion- 
ally they  make  a  case  or  sac  which  they  carry  about  with  them, 
and  in  which  they  are  more  or  less  protected. 

We  have  several  more  or  less  troublesome  species  that  are 


The  clover-hay  worm,  i  and  2;  its  cocoon  at  3; 
the  pupa  at  4  ;  the  moths,  Asopia  costalis,  at  5  and 
6  ;  at  7  the  tubes  made  by  the  larvae. 


THE    INSECT    WORLD. 


313 


rather  difficult  to  deal  with.  One  of  these  is  the  Mincola  vaccinii, 
or  "cranberry-fruit  worm,"  which  lives  in  the  berry  itself,  feed- 
ing in  the  seed-capsule,  causing  the  fruit  to  redden  up  prema- 
turely, and  then  to  dry  and  shrivel  on  the  vine.  A  single 
caterpillar  may  eat  into  every  berry  upon  a  fruit  stem  in  the 
course  of  its  existence,  then 


descends  to  the  ground,  and 
among  the  leaves  and  rub- 
bish spins  a  tough  little  co- 
coon in  which  the  pupa 
winters  safely,  even  if  cov- 
ered by  water.  The  eggs 
are  laid  about  the  middle  of 
July,  singly,  on  the  berries 
where  the  blossoms  have 
dropped  off,  under  one  of 
the  little  triangular  flaps. 
Once   the  larvae   are   in  the 


Fig.  357- 


\;^ 


Cranberr>-fruit   worm,  Mineola  vaccinii. — 

a,  cranberry  on  which  (b,  c)  the  eggs  are  laid  ; 

,  .  .  r      ^<  '^rva ;  e,/,  pupa  and  its  tip  ;  g,  cocoon  ;  It, 

berries  there  is  no  way  of  moth, 
getting  at  them,  and,  practi- 
cally, the  only  method  of  reducing  their  numbers  is  to  pick  the 
berries  as  early  as  may  be,  being  careful  to  get  in  all  that  are 
infested.  By  sorting  promptly  these  can  be  destroyed  before 
the  larvae  leave  them,  lessening  greatly  the  number  of  moths  for 
the  following  year.  The  insect  is  much  more  troublesome  in 
New  England  than  in  New  Jersey  or  in  the  northwestern  marshes. 

Nearly  allied,  but  with  totally  different  habits,  is  the  Mineola 
indighiel/a,  or  "rascal  apple-leaf  crumpler,"  so  called  from  its 
habit  of  making  irregular,  crumpled  cases  on  the  apple  leaves 
upon  which  the  insect  feeds.  It  is  rather  easily  reached,  where  it 
becomes  troublesome,  by  the  arsenical  sprays,  and  in  orchards 
where  spraying  is  generally  practised  it  is  incidentally  destroyed. 
Many  other  of  these  little  species  are  found  on  our  cultivated 
crops,  but,  as  a  rule,  in  such  small  numbers  as  to  be  hardly  no- 
ticeable, and  only  occasionally  a  species  becomes  locally  injurious. 

One  of  the  largest  of  our  Eastern  species  is  the  Melitara  pro- 
denialis,  which  feeds  inside  the  leaves  of  the  prickly  pear  or 
common  cactus  of  the  sandy  regions  south  of  Long  Island,  while 
its   near  ally,  M.  dentata,  is  found  in  an  allied  cactus  in  Kansas 


314 


AN   ECONOMIC   ENTOMOLOGY. 
Fig.   -^60. 


Fig.  361. 


Fig.  360,  the  Mediterranean  flour-motli,  Ephestia  kuktiiella. — a,  larva;  i^,  pupa;  c,/,  ailult 
with  wings  spread  and  at  rest ;  ff,  wing  of  a  variety  ;  d,  e,  h,  i,  structural  details.  Fig.  35S, 
Melitaru  prodenialis. — o,  larva  ;  b,  c,  d,  details  of  same  ;  e,  cocoon  ;  /,  pupa ;  g,  moth.  Fig. 
361,  the  bee-moth,  Galleria  melonella. — a,  larva  ;  b,  cocoon  ;  c,  pupa  ;  d,  e,  moths. 


THE    INSECT   WORLD. 


315 


and  the  Western  plains  generally.  This  caterpillar,  at  first  sight, 
resembles  one  of  tlie  Noctuids  very  closely,  and  is  of  a  beautiful, 
cjuite  unusual,  bluish  tint.  The  moth  expands  nearly  two  inches, 
and  is,  perhaps,  the  largest  of  those  belonging  here.  It  has  the 
peculiar  habit  of  laying  its  eggs  one  upon  the  other  in  a  pile 
which  mimics  the  spines  on  the  cactus  leaves  ;  so,  unless  carefully 
sought  for,  they  are  easily  overlooked.  We  find  also  in  this 
group  of  variable  habits  a  species  that    is  carnivorous,   Lcetilia 

^'•t;.  359- 


An  egg-stack  o(  Melilara prudeuialis. — Single  eggs  shown  al  a. 


coccidivora,  which,  as  its  name  indicates,  feeds  upon  scale  insects. 
Unfortunately,  it  is  altogether  too  rare  to  be  of  any  practical  use, 
and  is  simply  a  curiosity,  the  carnivorous  tendency  in  the  Lepi- 
doptera  being  extremely  rare. 

Ephestia  kuhniella  is  another  troublesome  species,  commonly 
known  a:3  the  "Mediterranean  flour-moth."  It  is  sometimes 
abundant  in  barns  and  mills,  and,  especially  in  the  latter,  may  do 
much  injury.  Great  complaint  has  been  made  during  the  few 
years  last  past,  the  insects  seeming  to  become  more  abundant 
and  to  cover  an  increasing  portion  of  our  territory.  Cleanliness, 
of  course,  is  primarily  to  be  enforced  ;  but  where  they  are 
abundant  enough  to  make  it  important,  the  insects  can  be  cleared 
out  by  using  bisulphide  of  carbon.  All  the  rooms  should  be 
tightly  closed  overnight,  and  enough  bisulphide  evaporated  to 
fiU  every  nook  and  cranny  with  the  poisonous  fumes.  In  a 
badly  infested  establishment  a  second  application  may  be  neces- 
sary in  some  cases,  but  in  most  instances  one  has  proved  effectual. 


3i6 


A  A'   ECONOMIC   ENTOMOLOGY. 


A  very  curious  species  is  the  Galleria  melonella,  or  "bee- 
moth,"  which  infests  beehives  and  feeds  upon  wax.  A  brood 
of  these  caterpillars  sometimes  invade  a  hive  and  bore  into  the 
wax  out  of  sight  of  the  bees,  frequently  demoralizing  them  to 
such  an  extent  that  they  abandon  their  home,  seeming  unable  to 
find  a  way  of  dealing  with  this  kind  of  enemy.  In  the  recent 
types  of  hives  there  is  little  opportunity  for  these  pests  to  estab- 
lish themselves,  and  if  the  bee-keeper  is  on  the  alert,  he  will  at 
once  perceive  any  such  invasion.  It  is  easy  then,  by  transferring 
and  cleaning  out  the  infested  frames,  to  save  the  swarm.  The 
moths  are  rather  curious  creatures,  mottled  and  streaked  on  the 
fore-wings,  the  outer  margins  of  which  are  also  a  little  excavated. 

Under  the  general  term  Crambids  we  may  describe  a  series  of 
species  with  slender  body,  narrow,  rather  squarely  cut  off  fore- 
wings,  and  broad  hind  wings.     When  at  rest  the  wings  are  rolled 

*  Fig.  362. 


Crambus  V7ilvivagellus. — a,  larva  ;  b,  over-,  and  c,  underground  tube  and  cocoon  ;  rf,  e, 
/,  moths  with  wings  spread  and  at  rest ;  g,  an  egg  much  enlarged. 


up  or  folded  closely,  giving  the  insect  a  little  the  appearance  of  a 
tiny  cylinder.  The  head  is  small,  not  at  all  retracted,  and  usually 
furnished  with  very  long  palpi  that  project  straight  out  like  a 
snout ;  as  a  whole,  resembling  somewhat  one  of  the  groups  of  the 
deltoid  Noctuids.  The  fore-wings  are  generally  white  or  yellow- 
ish, quite  frequently  streaked  or  spotted  with  silver  and  gold  ; 


THE    INSECT    WORLD.  317 

but,  of  course,  as  in  other  grouj^s,  we  have  modest  species  in 
wliich  gray  predominates,  and  where  the  longitudinal  markings 
are  rather  in  the  form  of  black  lines  or  streaks.  The  majority  of 
the  species  belong  to  the  old  genus  Crambus,  and  a  number  of 
them  are  injurious  in  grass  lands,  where  the  caterpillars  are 
known  as  "  root  web-worms."  As  in  many  other  cases,  it  is  not 
so  much  the  grass  that  is  injured  as  the  corn  crop  which  follows 
it,  and,  therefore,  we  usually  find  them  injurious  in  proportion 
to  the  length  of  time  that  a  field  has  been  in  grass  before  being 
ploughed  for  corn.  Usually  the  moths  appear  quite  early  in  spring, 
and  the  eggs  are  laid  in  grass  some  time  in  May,  loosely  attached 
to  blade  or  stem,  or  sometimes  simply  dropped  on  the  ground. 
The  larvae,  when  they  begin  feeding,  make  a  loose  web  or  tube 
of  silk,  sometimes  on  the  surface,  sometimes  a  little  below  it. 
Occasionally  they  feed  upon  the  roots,  sometimes  on  the  stalk, 
and  often  they  enter  antl  bore  into  the  plant  itself.  If  an  infested 
grass-plot  is  ploughed  after  eggs  have  been  laid  or  after  the  cater- 
pillars have  hatched,  such  of  them  as  survive  attack  the  corn,  if 
that  is  the  crop  planted.  Occasionally  entire  fields  are  destroyed, 
while  quite  frequently  much  damage  is  done.  The  moths  make 
their  second  appearance  a  little  after  midsummer,  and  are  never 
troublesome  then,  because  the  eggs  are  laid  in  grass  lands,  where 
the  caterpillars,  though  abundant,  are  not  noticed.  From  this 
general  life  history  it  will  be  seen  that  fields  can  be  kept  clear  by 
fall  ploughing,  or  by  turning  the  sod  very  early  in  spring  before  the 
moths  have  made  their  appearance  or  had  an  opportunity  to  de- 
posit eggs.  Bare  ground  will  not  become  infested,  nor,  usually, 
will  a  corn-field  if  there  is  any  grass  in  the  vicinity.  Where 
injury  is  caused  on  lands  ploughed  late,  I  have  found  that  certain 
commercial  fertilizers  exercise  a  beneficial  effect  ;  in  fields  fertil- 
ized with  potash  in  the  form  of  kainit  or  muriate,  the  exemption 
may  be  complete,  while  in  adjacent  plots  fertilized  with  barn- 
yard manure,  injury  may  be  serious.  It  is  also  possible  to  pre- 
vent trouble  by  planting  some  other  crop  between  sod  and  corn, 
where  such  rotation  can  be  profitably  adopted. 

In  the  genera  Diatma  and  Chilo  we  have  insects  resembling 
those  already  described,  but  rather  larger,  v/ith  often  more  slen- 
der pointed  wings  and  longer  palpi  and  abdomen.  Here  the 
larvae  are  usually  borers,  some  in  corn,  some  in  sugar-cane,  and 


3i8 


AN   ECONOMIC  ENTOMOLOGY. 


Fig.  366. 


some  in  other  plants.  As  with  all  other  borers,  there  is  difficulty 
in  reaching  them  directly,  and  besides  destroying  infested  plants, 
nothing  really  satisfactory  has  been  proposed.  Diatrcea  saccha- 
ralis  bores  into  sugar-cane  and  into  corn,  often  doing  much  in- 
jury to  the  latter  crop  in  the  States  south  of  the  Potomac. 
There  are  two  or  more  broods,  depending  on  latitude,  the  last 
remaining  through  the  winter  in  the  larval  stage  in  the  corn- 
stalks. We  have  thus  an  obvious  remedy  in  removing  and 
destroying  or  using  these  up  completely  before  the  spring  follow- 
ing. In  sugar-cane  the  matter  is  not  so  simple  ;  but  by  burning 
tops,  cutting  close  to  the  surface,  and  planting  in  fall  from  sound 
canes  only,  the  injury  can  be  at  least  much  reduced  if  not  en- 
tirely avoided.  It  is  another  in- 
stance where  an  intelligent  farm 
practice  will  answer  every  pur- 
pose, without  a  resort  to  insecti- 
cides of  any  kind.  Mats,  both 
flat  and  round,  are  especially  to  be 
avoided  for  affected  canes. 

An  interesting  little  family  is 
the  Pterophoridce,  peculiar  in 
having  the  wings  split  into  feath- 
ers or  plumes.  Occasionally  the 
primaries  have  only  a  cleft  that 
does  not  extend  beyond  the  mid- 
dle, but  sometimes  they  are  split 
for  the  full  length.  The  hind 
wings  may  be  divided  into  from 
four  to  six  feathers,  the  insects 
being  therefore  termed  "plume 
moths, "  or  "  feather-wing  moths. ' ' 
As  a  whole,  few  of  the  species  are 
common,  and  I  am  acquainted 
with  only  one  that  is  in  any  way 
injurious, — the  "grape  plume," 
The  caterpillar  of  this  is  pale  yel- 
lowish or  nearly  white,  with  little  tubercles,  from  which  rise  tufts 
of  pale  hair  similar  to  those  of  some  Arctiids,  or  "  woolly  bears." 
It  lives  in  the  tips  of  young  shoots  of  grape,  webbing  up  the 


The  grape  plume,  Oxyptilus  peris- 
celidactylus. — a,  larvae  in  a  spun-up 
tip;  d,  pupa;  c,  its  breast  projection  ; 
rf,  moth  ;  <?,  a  single  segment  of  larva. 


Oxyptihis  periscelidadylus. 


THE    IXSECT   WORLD. 


319 


terminal  leaves  soon  after  growth  has  started,  and  eating  out  the 
heart.  It  would  seem  thus  as  if  considerable  injury  might  be 
caused,  but  really  this  is  not  so,  because  in  most  cases  they  do 
not  attack  the  shoots  until  the  buds  have  become  freed, — that 
is  to  say,  the  shoots  are  attacked  above  the  flower  cluster,  so 
that  no  injury  is  done  to  the  resulting  crop.  When  the  insects 
disappear,  which  they  do  quite  early,  the  shoot  simply  sends  out 
a  new  spur  from  the  last  leaf,  and  the  effect  of  their  presence  is 
scarcely  noticed.  Practically,  there  is  no  method  of  checking 
their  increase,  except  by  picking  off  the  infested  tips  or  crushing 
the  caterpillars  within  the  webbed  leaves. 

We  have  another  scries  of  families  grouped  under  the  Tortri- 
cids,  sometimes  called  "bell-moths,"  from  their  peculiar  appear- 
ance when  at  rest,  but  more  commonly  "  leaf- rollers,"  from  the 
quite  usual  larval  habit  of  folding  or  rolling  up  the  edges  of 
leaves.  We  have  a  number  of  troublesome  insects  in  this  series, 
and  some  of  them  are  not  easy  to  deal  with.  The  moths  are 
quite  easily  recognized  by  their  broad,  short  fore  wings,  forming  a 


Fig.  367. 


Tcras  minnta. — a,   larva  ;    b,   pupa  ; 
moth  ;  (f,  case  made  on  apple-leaf. 


Fig.  368. 


Rhopobota  vaccuiiaiia. 


more  or  less  obvious  shoulder  on  the  front  margin.  These  wings 
are  held  roof-like,  the  edges  overlapping  only  a  little  at  the 
middle  of  the  back,  and  completely  conceal  the  moderate  or 
small  hind  wings.  Their  colors  are  frequently  bright  and  con- 
trasting, while  in  other  cases  they  are  uniform  and  sombre,  the 
entire  insect  inconspicuous  and  unattractive.  One  of  the  com- 
mon species  is  Teras  minida^  whose  larva  attacks,  among  others, 


320 


AN   ECONOMIC   ENTOMOL  OGY. 


apples  and  cranberries  :  in  apples  simply  feeding  upon  the  leaves 
in  a  little  case,  but  on  cranberries  often  becoming  seriously  injuri- 
ous by  spinning  up  and  eating  the  tips  of  the  growing  shoots.  It 
also  feeds  on  huckleberry  and  allied  plants,  and  from  them  goes 
to  cultivated  cranberry  bogs.  It  is  there  known  as  the  "fire- 
worm,"  and  it  is  distinguished  from  Rhopobota  vacciniana, 
another  caterpillar  with  the  same  habits,  by  having  a  yellow  in- 
stead of  a  black  head.  Both  these  insects  have  similar  larval 
habits,  but  the  Rhopobota  has  only  two  broods,  and  hibernates  m 
the  ^^g  stage,  while  the  Teras  has  three,  and  hibernates  as  an 
adult.  There  is  a  curious  alternation  of  generations  in  this  in- 
sect, the  summer  broods  being  yellow  or  orange,  while  the  moths 
that  hatch  in  the  fall  and  hibernate  are  uniformly  slate-gray. 
Cultivated  cranberry  bogs  are  covered  with  water  during  the 
winter,  and  the  moths  cannot  hibernate  on  them  ;  so,  as  they  lay 
their  eggs  quite  early  in  spring,  if  the  bogs  are  kept  covered 
until  all  other  vegetation  has  started,  they  oviposit  elsewhere, 
leaving  the  bogs  free.  Therefore,  holding  the  water  late,  say 
until  at  least  the  middle  of  May,  is  usually  a  fairly  complete  pro- 
tection. The  Rhopobota  lays 
Fig.  369.  j(.g  eggs  upon  the  cranberry 

plants  late  in  summer.  They 
remain  unaffected  by  the 
water  with  which  the  bog  is 
covered  until  spring,  then 
hatch,  and  the  larvae  spin  up 
the  tips  precisely  as  in  the  case 
of  the  Teras,  the  moths  com- 
ing to  maturity  early  in  July. 
Eggs  for  a  second  brood  are 
then  laid,  and  these  are  some- 
times sufficient  in  number  to 
sweep  entire  bogs,  giving  them  the  appearance  of  having  been 
burned  over,  wherefore  this  insect  has  also  been  called  "fire- 
worm."  As  against  this  species,  late  holding  the  water  is  not  so 
effectual,  because  it  must  be  kept  on  until  sufficiently  warm  to 
induce  the  eggs  to  hatch,  the  young  larvae  dying  as  soon  as  they 
break  the  egg-shell,  or  stifling  before  they  are  really  born.  The 
method  is  feasible  on  a  flat  bog  where  water  can  be  drawn  down 


Cranberry  leaf  with  eggs  of  Rhopobota,  and 
a  spray  spun  up  at  tip  by  the  larva. 


rilE    IXSECT    WORLD. 


321 


SO  as  to  warm  up  rapidly,  but  there  is  danger  in  holding  too  long, 
because  if  the  plants  start  under  water,  as  they  sometimes  do,  the 
crop  is  ruined.  Occasionally,  however,  it  pays  to  lose  a  crop 
in  whole  or  in  part,  to  free  the  bogs  completely  of  this  insect,  as 
they  will  then  remain  practically  safe  for  several  years  in  succes- 
sion. Where  water  is  abundant  and  the  bogs  can  be  readily 
reflowed,  the  practice  of  the  present  day  is  to  draw  the  water 
early  to  induce  an  early  hatching  of  the  insects,  and  as  soon  as 
the  larv?e  generally  appear,  reflow,  leaving  on  the  water  at 
least  twenty-four  hours.  This  will  not  hurt  the  plants  at  that 
period  of  their  growth,  and  will  kill  every  caterpillar  upon  the 
bog.  The  effect  depends  largely  upon  the  care  with  which  it  has 
been  done  and  upon  the  judgment  exercised  as  to  the  proper 
time.  It  should  be  de- 
layed until  the  great  ma-  Fig.  370. 
jority  of  the  eggs  have 
hatched,  but  should  not 
be  delayed  so  as  to  run  the 
risk  of  injuring  the  plants. 
In  the  genus  Caccecia 
we  have  several  injurious 
species,  and  none  more  an- 
noying than  C.  rosaceana.      „        ,    .    ,,       ^       . 

-'_      '^  Rose    leaf-roller,     Caccecia     rosaceana. — Larva, 

This   attacks   a   great  va-  pupa,  and  adult. 

riety  of  plants,  but    it   is 

most  troublesome  on  roses,  spinning  and  folding  leaves  and  buds 
and  so  destroying  the  flowers.  These  larvae  are  not  easily  dealt 
with,  but  spraying  the  plants  with  pyrethrum  or  kerosene  emul- 
sion as  soon  as  the  first  signs  of  injury  are  observed  will  generally 
serve  to  keep  them  down.  On  a  small  scale  they  may  be  con- 
trolled by  compressing  the  spun-up  leaves  and  killing  the  cater- 
pillar in  its  home. 

Some  of  the  species  live  in  communities,  making  a  nest  or 
web,  and  such  is  the  Caccecia  fervidana,  the  caterpillar  of  which 
lives  on  oak,  and  spins  up  the  shoots  of  young  trees  or  the  tips 
of  the  branches  of  older  ones.  In  some  cases  the  nests  become 
from  three  to  six  inches  in  diameter,  and  when  the  caterpillars 
have  reached  their  full  growth  they  pupate  within  it,  wriggling 
out  through  the  silken  covering  when  ready  to  emerge  as  moths, 


AN   ECONOMIC  ENTOMOLOGY. 


and  leaving  the  empty  pupa  cases  projecting  all  around.  Some 
species  are  occasionally  so  numerous  that  the  nests  constructed 
by  them  become  enormous, — four  or  five  feet  in  height,  and 
covering  young  trees  entirely.  This  and  other  species  having 
the  same  habit  can  be  dealt  with  by  early  spraying,  or,  when 
feasible,  by  picking  off  the  webbed  leaves  or  shoots. 

The  best  known  of  all  belonging  to  this  family  is  the  ' '  codling 
moth,"  Carpocapsa pomonella,  and  there  is  no  insect,  except  possi- 
bly the  ' '  plum  curculio, ' '  that  has  done  more  injury  to  our  orchard- 
ists.     The  moth  appears  at  about  the  time  the  apple-trees  are  in 

blossom,  and  lays  a  single 
■^^  ■  egg  upon  the  young  fruit  at 

the  point  where  the  blossom 
has  dropped  off.  In  a  few 
days  the  caterpillar  hatches, 
eats  a  little  on  the  outside 
for  a  day  or  two,  and  then 
makes  its  way  into  the  fruit 
itself,  feeding  around  the 
seed-capsule  or  core,  and 
making  the  well-known 
"worm"  in  the  apple.  Oc- 
casionally two  or  more 
moths  may  oviposit  on  the 
same  fruit,  and  this  ac- 
counts for  the  two  or  more 
larvae  sometimes  found  in 
one  apple.  Except  in  the 
northern  part  of  the  country, 
there  are  two  broods,  the 
first  caterpillars  becoming  full-grown  and  leaving  the  apples  about 
midsummer,  changing  very  soon  thereafter  to  moths,  which  lay 
the  eggs  for  the  larvae  found  in  the  ripe  apples.  The  second 
brood  does  not  so  usually  oviposit  at  the  blossom  end,  but  seems 
to  have  a  preference  for  the  point  where  two  fruits  touch,  for  we 
often  notice  that  in  a  little  bunch  of  apples  every  one  is  infested, 
the  entrance  in  all  cases  being  just  at  the  point  of  contact.  In  any 
event,  whether  there  is  one  brood  or  two,  the  caterpillars  of  the 
last,  when  full-grown,  leave  the  apples,  find  a  hiding-place  under 


The  codling  moth,  Carpocapsa  pomonella. — a, 
apple  cut  to  show  borings  of  the  l.irva  ;  b,  place 
where  the  egg  was  laid  and  the  larva  started  ; 
rf,  pupa ;  e,  larva  ;  f,  g,  moths  at  rest  and  with 
wings  spread  ;  h,  head  of  larva ;  ?',  cocoon. 


7 HE    INSECT   WORLD. 


323 


a  scale  of  bark  or  in  a  little  depression,  and  there  spin  a  cocoon, 
in  which  they  remain  unchanged  during  the  winter.  The  change 
to  the  pupa  takes  place  very  early  in  spring,  and  the  moths  appear 
as  already  stated.  It  has  been  found  that  we  are  able  to  protect 
our  trees  by  spraying  them  with  one  of  the  arsenites  as  soon  as 
the  blossoms  have  all  dropped  and  the  fruit  is  well  set.  At  that 
time  the  young  apj^lcs  are  upright,  affording  a  favorable  oppor- 
tunity for  lodging  the  poison  in  the  caly.x  cup,  and  here  it  remains 
until  the  larva  makes  its  first  and,  if  the  spraying  is  properly  done, 
its  last  meal.  Under  favorable  circumstances  a  single  spraying  is 
sufficient  to  prevent  injury,  but  practically  two  sprayings  are  re- 
quired at  intervals  of  about  a  week,  and  a  third  if  rain  interferes 
to  shorten  this  period, — that  is  to  say,  one  just  as  soon  as  the 
blossoms  are  all  off,  and  the  second  about  a  week  or,  if  the 
weather  remains  dry,  at  most,  ten  days  thereafter.  This  is  to 
allow  for  the  irregular  hatching  of  the  larvae,  the  rapid  growth  of 
the  young  fruit,  and  to  make  certain  that  all  may  be  reached.  It 
is  here  that  promptness  and  thoroughness  will  tell.  To  be  ef- 
fective the  spraying  inicst  be  done  before  the  larvae  hatch,  and 
the  mixture  7)11181  be  on  every  fruit  to  be  protected.  In  dry 
weather  ten  days  between  sprayings  is  not  too  much  ;  in  wet  or 
showery  weather  three  days  may  be  too  long.  The  young  larva 
feeds  externally  for  a  day  or  two  only,  and  unless  it  is  then  killed, 
is  beyond  our  reach.  Success  is  the  result  of  keeping  an  un- 
broken film  of  poison  on  the  flower  end  of  each  fruit  until  all 
eggs  are  hatched.  One  pound  of  Paris  green  or  London  purple 
in  one  hundred  and  fifty  gallons  of  water  is  a  good  strength,  or 
fifteen  ounces  of  arsenate  of  lead  in  one  hundred  gallons.  Some 
growers,  however,  use  a  mixture  of  double  this  strength  and  find 
it  advantageous  ;  they  spray  carefully,  use  just  enough  to  cover, 
and  risk  a  little  burning  of  the  foliage. 

The  last  series  in  the  order  is  the  Tmema,  or  the  "  Tineid 
moths,"  comprising  the  smallest  of  the  Lepidopterous  insects. 
There  is  an  enormous  number  of  species,  and  we  know  very 
little  about  the  great  majority  of  them.  With  few  exceptions,  the 
insects  have  long,  narrow  wings,  the  primaries  pointed,  the  sec- 
ondaries lanceolate,  but  their  surface  increased  by  enormously 
long  fringes,  which  are  in  many  cases  broader  than  the  wings 
themselves,     They  often  have  on  the  head  a  clothing  of  upright 


324 


AN   ECONOMIC  ENTOMOLOGY. 


divergent  scales,  all  of  one  height,  giving  somewhat  the  appear- 
ance of  a  little  plush  cap.  In  their  life  habits  they  vary  much. 
Some  are  leaf-miners,  living  between  the  upper  and  under  sur- 
faces, and  each  species  eating  out  characteristic  galleries  that  are 
visible  as  irregular  brown  lines  or  blotches.  Others  are  case- 
bearers,  making  little  houses  of  various  shapes  and  texture, 
which  they  carry  about  with  them,  and  in  which  they  live,  pro- 
jecting the  head  and  anterior  segments  just  far  enough  to  feed, 

Fig.  373. 


Apple  case-bearer,  Coleophora  nialivorella. — a,  larval  cases;  b,  larva;  c,  pupa; 
d,  adult  moth. 

but  retreating  at  the  first  signs  of  disturbance.     A  few  feed  openly, 
while  others  are  borers  in  fruits,  seeds,  or  even  twigs. 

Among  the  best  known  are  the  "clothes  moths," — little,  yel- 
lowish creatures  often  seen  flying  in  houses  early  in  the  evening, 
and  which  generally  arouse  excitement  and  resentment  in  the 
breast  of  the  careful  housekeeper,  for  she  knows  that  her  woollens 
and  furs  are  in  danger.  The  caterpillars  feed  upon  animal  tex- 
tiles of  all  kinds,  and  upon  furs  and  feathers.  They  do  not  often 
attack  vegetable  fibre  like  cotton  or  linen.  Their  habit  is  to 
form  a  little  flattened  case  of  fibres  from  the  material  upon  which 
they  are  feeding,  and  this  is  lined  on  the  inner  side  with  silk.  In 
about  three  weeks  the  larva  is  full  fed,  changes  to  a  pupa  within 
its  case,  and  the  moth,  when  it  emerges,  leaves  the  empty  shell 
protruding  for  half  its  length.     There  are  several  species  engaged 


THE    INSECT    WORLD. 


325 


E^'y 


-.t: 


iD. 


\t«' 


%:^ 


[1,1 


^  AT, 


*!»— ^■^:« 


326  AN  ECONOMIC  ENTOMOLOGY. 

in  this  pleasant  occupation,  but  they  have  habits  so  nearly  sim- 
ilar that  there  is  no  necessity  for  differentiating  them  here.  As 
to  remedies,  plenty  of  air,  sunshine,  and  beating-  will  keep  cloth- 
ing free,  or,  having  been  made  free,  it  can  be  wrapped  in  stout 
paper  in  such  a  way  as  to  make  it  impossible  for  the  moths  to 
enter  and  to  lay  eggs,  or  for  the  young  caterpillar  to  find  a  crev- 
ice through  which  to  crawl.  A  cotton  or  linen  sack,  if  the  material 
is  sufficiently  dense,  will  afford  almost  equal  protection.  A 
closet  or  trunk  in  which  plenty  of  naphthaline  crystals  have  been 
strewn  is  also  a  safe  place,  and  will  be  avoided  by  the  moths,  who 
cannot  live  in  such  an  atmosphere.  Where  the  insects  get  into 
carpets,  they  can  be  destroyed  by  saturating  the  infested  spots 
with  gasoline,  as  this  is  exceedingly  penetrating  and  fatal  to  the 
insects  wherever  it  touches  them. 

Another  troublesome  species  is  the  Gelechia  cereallella,  or  ' '  An- 
goumois  grain  moth."  Its  larva  bores  into  the  kernels  of  wheat, 
rye,  or  corn,  a  single  grain  of  wheat  sufficing  to  bring  one  to 
maturity,  while  in  a  grain  of  corn  two  or  three,  or  sometimes 
even  four,  larvae  find  sufficient  nourishment,  though  two  is,  per- 
haps, the  rule.  The  insects  sometimes  lay  their  eggs  upon  the 
grain  in  the  fields,  and  when  it  is  cut  and  brought  into  the  barn 
they  continue  breeding  in  the  mow  so  long  as  it  remains  there. 
Corn-cribs  frequently  become  infested,  and  the  insects  breed  as 
long  as  the  temperature  remains  mild.  Where  grain  is  threshed 
and  bulked  the  upper  layers  may  be  infested,  but  the  insects  are 
not  able  to  get  in  very  far,  because  the  moth  is  unable  to  escape 
through  any  heavy  layer,  becoming  worn  out  and  dying  before 
reaching  the  surface.  The  insect  is  much  more  troublesome 
southward  than  it  is  in  the  north,  where  the  cold  weather  checks 
breeding  before  it  has  an  opportunity  to  do  much  damage  ;  but 
in  regions  where  the  temperature  in  the  barns  is  moderate 
throughout  the  winter  it  frequently  does  great  injury.  The 
best  remedy  is  threshing  and  bulking  the  grain  as  soon  as  pos- 
sible, covering  the  bins  to  keep  out  the  insects.  If  infection  is 
noticed,  it  can  be  easily  checked  by  evaporating  bisulphide  of 
carbon  in  a  dish  upon  the  surface.  The  vapor  is  heavy  and 
sinks  through  it  to  the  bottom,  effectually  clearing  out  any  in- 
sects that  may  be  present.  In  corn-cribs  the  bisulphide  can  also 
be  used,  but  the  crib  must  be  temporarily  closed  by  canvas  or 


THE    INSECT   WORLD.  327 

sheeting,  so  that  the  vapor  may  become  effective  before  it  escapes. 
It  has  been  found  by  experiment  that  grain  can  be  exposed  to 
this  vapor  for  a  considerable  time  without  losing  in  germinating 
qualities,  but  seed  wheat  should  be,  if  possible,  kept  free  from 
such  insects.  It  should  be  selected  early  and  kept  in  insect-tight 
vessels  until  needed  for  use.  Open  corn-cribs  should  be  placed 
in  such  a  way  as  to  get  the  benefit  of  all  the  cold  weather  there 
is,  and  thus  the  multiplication  of  the  insects  will  be  checked  so 
early  that  no  serious  damage  will  be  done. 

There  are  other  species  of  Tineids  infesting  cultivated  plants, 
but  few  are  widely  distributed  and  at  the  same  time  injurious. 
In  most  cases  the  application  of  arsenites  to  those  forms  feeding 
openly  upon  plant  tissue  proves  more  or  less  satisfactory,  while 
against  those  feeding  upon  stored  products  we  can  use  the 
bisulphide  of  carbon. 


CHAPTER    VIII. 

THE    DIPTERA,    OR   FLIES. 

The  term  Diptcra  means  two-winged,  and  members  of  this 
order  are  separable  from  all  other  insects  by  possessing,  nor- 
mally, only  a  single  pair  of  wings.  These  are  borne  by  the 
middle  segment  of  the  thorax,  and  are,  therefore,  the  first  pair  ; 
the  second  or  hind  pair  are  reduced  to  little  club-like  processes 
called  "  halteres,"  "poisers,"  or  "  balancers."  Their  function 
is  supposed  to  be  indicated  by  the  last  of  these  terms, — i.e.,  to 
aid  the  insect  in  directing  its  flight  and  maintaining  its  position  in 
the  air.  The  members  of  the  order  are,  therefore,  easily  recog- 
nizable in  most  instances,  but  the  reference  of  individual  speci- 
mens to  the  proper  place  in  the  system  is  a  matter  of  greater 
difficulty.  They  are  mostly  of  moderate  or  small  size,  sometimes 
quite  fragile,  and  the  character  of  the  wing  venation,  upon  which 
much  reliance  is  placed  in  scientific  classification,  is  not  readily 
made  out,  except  by  the  special  student.  Yet  a  litde  patience 
will  generally  lead  to  the  proper  group,  and  the  habits  or  life  his- 
tory may  then  be  used  to  determine  more  closely. 


328  AN  ECONOMIC   ENTOMOLOGY. 

Before  taking  up  the  more  typical  forms,  we  may  briefly  con- 
sider the  Aphaniptera,  or  fleas,  which  are  usually  considered  as 
flies  that  have  lost  their  wings  as  a  result  of  parasitic  habits. 
They  are  small,  transversely  flattened  creatures,  usually  brown 
in  color,  with  small  heads,  piercing  mouth  parts,  and  the  merest 
rudiments  of  wing-pads.  To  replace  wings,  they  are  furnished 
with  greatly  developed  posterior  legs  fitted  for  jumping,  and  in 

Fig.  377. 


Rabbit  flea,  much  enlarged. 

proportion  to  their  size  their  leaps  are  wonderful.  They  live  in 
the  adult  stage  among  the  hair  of  warm-blooded  animals,  sucking 
blood,  their  form  enabling  them  to  move  about  easily  in  even  the 
thickest  fur.  So  also  the  position  of  the  spines  clothing  the 
body  is  such  that  every  effort  of  the  insect  pushes  it  forward, 
which  accounts  for  the  difficulty  in  holding  a  specimen  when 
captured. 

The  larvae  are  whitish,  small,  worm-like  creatures,  almost  cylin- 
drical in  form  and  with  small  brownish  heads  which  bear  fairly 
well  developed  mouth  parts.  They  live  upon  partly  decayed 
matter  in  or  near  the  lairs  of  the  animals  upon  which  the  adults 
feed,  and  the  eggs  are  probably  dropped  at  hap-hazard  by  the 
females  while  the  host  is  at  rest.  A  rug  used  as  a  bed  for  a  dog 
or  cat  may  be  found  full  of  eggs  at  almost  any  time  during  spring 


THE    INSECT   WORLD. 


329 


or  summer,  the  larvce  finding  food  in  any  dust  or  dirt  near  by. 
The  spaces  between  the  boards  of  floors  are  often  filled  with  them, 
and  a  little  pile  oi  moist  sawdust  or  shavings  may  harbor 
myriads.  This  led  to  a  quite  wide-spread  and  at  one  time  popu- 
lar belief  that  under  such  circumstances  the  insects  were  sponta- 
neously generated.  The  period  of  development  is  very  brief, 
and  under  favorable  conditions  a  building  may  swarm  with  fleas 
in  a  month  or  two.  No  species  of  flea  specifically  infests  man 
in  this  country,  though  the  Ceratopsylhis  serraticeps  oi  \.\iQ.  house- 
hold dog  and  cat  often  bothers  him  a  little.  In  tropical  and 
subtropical  countries  several  species  attack  him  as  readily  as 
they  do  any  other  warm-blooded  animal. 

Where  a  house  becomes  infested,  the  dogs  or  cats,  if  any, 
should  be  washed  with  carbolic  soap  every  other  day  to  kill  the 
adults  on  them,  and  if  the  animals  be  allowed  to  run  throughout 
the  house  they  will  in  a  few  days  attract  all  the  fleas  to  them- 
selves, where  they  can  be  dealt  with.  The  sleeping  rugs  of  the 
animals  should  be  thoroughly  beaten  or  shaken  out-doors  every 
day,  and  the  most  rigid  cleanliness  should  be  everywhere 
observed. 

Where  dogs  or  cats  are  not  available  as  traps,  a  liberal  applica- 
tion of  gasoline,  following  a  thorough  cleaning  up,  is  the  best 
remedy.  It  should  be  poured  into  every  crevice  in  the  floor  and 
along  the  base-boards,  and  it  will  kill  every  larva  and  adult  with 
which  it  comes  into  contact.  The  liquid  is  exceedingly  inflam- 
mable, and  must  be  used  with  that  fact  borne  in  mind.  Pet 
animals  can  be  cleaned  by  a  free  and  frequent  use  of  carbolated 
soaps  or  vaseline. 

In  hot  countries  fleas  are  often  serious  pests,  not  only  to  man 
and  his  pets,  but  to  fowls  as  well,  young  chickens  being  fre- 
quently killed  by  the  great  numbers  clustering  around  their 
heads.  Here  the  free  use  of  carbolated  vaseline  is  indicated  to 
keep  off  the  insects  and  to  act  as  an  effective  healing  agent. 
Cleanliness  in  its  strictest  form  in  the  coops  and  houses  is  always 
indicated. 

Rather  more  serious  pests  are  the  so-called  "jigger"  fleas, 
species  oi  Sarcopsylla,  or  Vermipsylla,  the  females  of  which  work 
their  way  under  the  skin,  often  of  the  feet  of  man,  causing  an  ul- 
ceration in  which  the  eggs   and  larva;  develop.      If  the  case  is 


330  AN  ECONOMIC    ENTOMOLOGY. 

neglected,  amputation  sometimes  becomes  necessary.  Where 
shoes  are  worn,  the  insects  do  not  often  succeed  in  reaching  their 
favorite  points  of  attack  ;  but  if  they  do,  a  prompt  use  of  the 
needle  or  knife  or  a  mercurial  ointment  will  prevent  trouble.     A 

Fig.  378. 


'^  y\^^&["  ?i&'!i,Sarcopsylla  penetrans. — Female  distended  with  eggs,  from  side  and  front. 


Fig.  379. 


moist  quid  of  tobacco  bound  over  the  infested  spot  usually  re- 
sults in  killing  the  insects,  so  that  the  wound  can  be  cleaned  and 
left  free  to  heal. 

The  metamorphosis  of  the  fleas  is  complete,  like  that  of  the 

true  flies. 

The  most  obvious  division  among 
the  true  flies,  for  our  purpose,  is 
based  upon  the  character  of  the  an- 
tennae, or  feelers.  There  are  two 
series,  those  with  long  horns  or  feel- 
ers much  exceeding  the  head,  and 
those  with  short  horns,  having  usu- 
ally only  two  or  three  visible  seg- 
ments, one  of  which  is  often  fur- 
nished with  a  specialized  bristle,  or 
' '  arista. ' '  The  divisions  are  by  no 
means  sharply  limited  scientifically, 
but  are  sufficiently  distinct  for  the 
species  of  economic  importance. 

The  Tiptdidce,  or  ' '  crane-flies, ' ' 
is  the  first  family  of  economic  inter- 
est, and  its  members  are  recognizable  by  their  resemblance  to 
exaggerated  mosquitoes.  They  are  usually  quite  large,  with 
many-jointed,  slender,  thread-like  antennae  and  scarcely  shorter 
maxillary  palpi.      The  legs  are  abnormally  long  and  ungainly, 


Antennae  in  flies. — a,  tip  of  plu- 
mose antenna ;  b,  joints  verticil- 
late  ;  c,  aristate,  the  arista  bare ; 
rf,  arista  plumose  at  base  ;  e,  arista 
plumose  to  the  tip. 


THE    INSECT    WORLD.  33 1 

and  the  wings  are  narrow,  so  that  the  insect  is  awkward  in  ap- 
pearance, as  well  at  rest  as  in  its  flight,  which  is  slow  and  heavy. 
The  flies  are  most  frequently  seen  in  low,  rank  meadows,  or 
along  ditches  or  sluggish  streams,  flying  preferably  during  the 
morning  and  late  afternoon  hours.     The  larvae  are  slender,  cylin- 

FiG.  380. 


A  crane-fly,  Pachyrrhina  species. 

drical,  somewhat  worm-like,  of  an  extremely  tough,  leathery 
texture,  and  live  underground  on  the  roots  of  grasses,  or  in  de- 
caying wood.  In  Europe  they  are  known  as  "wire-worms," 
and  are  often  seriously  injurious  ;  but  in  North  America  none  of 
the  species  have  as  yet  proved  very  troublesome.  It  is  probable 
that  intelligent  farm  practice  Avill  be  sufiicient  to  control  any  of 
the  species  likely  to  become  injurious  with  us. 


33^ 


^N  ECONOMIC  ENTOMOLOGY. 


To  the  family  C2dicid(Z  belong  the  mosquitoes,  characterized 
by  a  slender  body,  long  legs,  long  antennae,  and  a  small  head 

with  mouth  parts  usually  ex- 
tended to  form  a  beak  or  pro- 
boscis. In  the  male  the  probos- 
cis contains  a  single  lancet  only, 
not  fitted  for  puncturing  animal 
tissues,  and  the  antennae  are  plu- 
mose ;  in  the  female  a  series  of 
five  slender,  bristle-like  lancets 
forms  an  effective  piercing  struct- 
ure, and  the  antennae  have  the 
joints  furnished  with  a  few  bristles 
only.  The  wings  are  slender  and 
scaly  along  the  veins. 

The  species  are  quite  numerous, 
and  while  most  of  them  are  pests 
of  the  first  order,  a  few  seem  to 
feed  on  other  than  animal  juices. 
The  more  common  species  be- 
long to  the  genus  Cidex,  in  which 
the  wings  are  unspotted,  the  palpi  of  the  female  are  shorter  than 
the  beak,  and  the  body  is  held  parallel  with  the  surface  upon 
which  the  insects  rest.  The  species  of  Anopheles  are  fewer  in 
number,  but  are  of  relatively  greater  economic  importance, 
because  they  have  been  proved  to  be  intermediate  hosts  for  the 
parasites  causing  ' '  malarial' '  fevers.  They  are  larger,  as  a  rule, 
than  Culex,  the  wings  are  more  or  less  spotted,  the  palpi  in 
both  sexes  are  as  long  as  the  beak,  the  body  is  more  linear  and 
is  held  at  an  angle  to  the  surface  upon  which  it  rests,  the  beak 
directed  to  a  point  almost  midway  between  the  fore  and  middle 
legs. 

Some  of  the  species  of  Culex  fly  or  allow  themselves  to  be 
carried  by  the  wind  for  long  distances,  so  that  they  occasionally 
appear  as  pests  many  miles  from  any  possible  breeding-place. 
The  mode  of  hibernation  varies  :  in  Anopheles  and  some  Culex 
the  female  adult  survives  ;  in  other  species  of  C^dex  the  eggs  lie 
over  in  suitable  localities,  and  in  one  instance  at  least  the  partly- 
grown  larva  lives  through  the  winter. 


Lan'a  and  pupa  of  the  Culex  pungens, 
enlarged  ;  with  anal  flaps  of  pupa  yet 
more  enlarged.  (From  Howard,  Bull.  25, 
n.  s.,  U.  S.  Dept.  Agl.,  Div.  Ent.) 


THE   INSECT   WORLD. 


333 


The  larvse  are  commonly  known  as  "  wrigg^lers,"  and  are  of 
two  general  types, — one  usual  in  Culcx  and  its  allies  in  which  the 
head  is  held  down  in  the  water  and  the  tail  or  anal  siphon  is  kept 
at  the  surface  ;  the  other  peculiar  to  Anopheles,  in  which  the  body 
rests  for  its  full  length  on  the  surface. 

All  the  larx'ce  breathe  through  a  single  spiracle  at  the  end  of 
the  anal  tube  or  siphon,  and  most  of  them  must  come  to  the 
surface  at  rather  short  intervals  to  secure  the  necessary  supply  of 
air.  When  startled  they  make  their  way  through  the  water  by  a 
peculiar  jerky  or  wriggling  motion,  which  gives  them  their  com- 
mon name. 

Eggs  are  laid  in  various  ways  :  sometimes  singly  on  water  or 
on  vegetation  in  water,  or  in  damp  places  where  water  is  likely 
to  come  ;  sometimes  they  are  laid  in  masses,  forming  "boats," 
which  float  on  the  surface  of  the  water,  and  this  is  the  habit  of 
our  most  common  species.  Under  proper  conditions  the  eggs 
hatch  quickly  and-  the  larvae  develop  in  accordance  with  the 
temperature  ;  a  week  or  ten  days  being  sufficient  to  carry  the 
insects  from  'i^^  to  adult  in  midsummer. 

The  lar\a  must  have  water  for  its  development,  but  there  is 
none  so  foul  and  none  so  salt  that  some  species  does  not  breed  in 
it.  There  is  no  space  here  for  methods  of  dealing  with  these 
pests  ;  but  measurable  exemption  from  annoyance  may  be  secured 
by  a  free  use  of  the  oil  of  citronella  on  exposed  parts  of  the  body. 

Mosquitoes  occur  all  over  the  world,  and  they  are  quite  as 
numerous  and  troublesome  in  the  arctics  as  they  are  in  the  tropics. 
In  fact,  the  climatic  peculiarities  of  parts  of  the  frigid  zone,  giving 
a  short  hot  summer  over  a  surface  soaked  with  water  from  melting 
snow,  produce  conditions  which  favor  their  development  in  great 
numbers.  In  permanent  ponds  or  streams  their  natural  enemies, 
of  which  there  are  many,  keep  them  down  to  insignificant  numbers. 

Closely  resembling  mosquitoes  in  appearance  are  the  Chiro- 
nomidt£,  which  may  be  recognized  by  the  naked  wings  and  by 
having  the  thorax  produced  so  as  to  hide  the  small  head  fi-om 
above.  The  antennae  are  feathered  in  both  sexes,  those  of  the 
male  strikingly  plumose.  To  this  family  belong  the  gnats  or 
midges  which  may  sometimes  be  seen  dancing  in  swarms  in  the 
evening  only  a  few  feet  above  ground,  generally  early  in  the 
year  and  in  damp  places.     The  larvae  are  mostly  aquatic,  and 


334 


AN   ECONOMIC  ENTOMOLOGY. 


never  economically  important.  The  minute  species  of  Ceratopo- 
gon  are  furnished  with  piercing  mouth  parts,  and  are  often  ex- 
tremely irritating,  but  otherwise  the  adults  are  harmless,  unfitted 
for  blood-sucking.    They  are  known  as  ' '  sand-flies, "  "  punkies, ' ' 

"gnats,"    "midges,"    and   by 
Fig.  382.  other    names,    some    of   which 

are  applied  indifferently  to  spe- 
cies of  diverse  families. 

The  "fungus  gnats"  of  the 
family  MycetophilidcB  are  also 
small,  mosquito-like  creatures, 
but  more  compactly  built,  with 
shorter  abdomen,  stouter  body 
and  legs,  and  antennae  that  are 
not  plumose  or  feathered  in 
either  sex.  They  are  smoky 
or  blackish  in  color,  as  a  rule, 
and  frequent  decaying  vegeta- 
ble matter  or  fungi,  in  which 
the  larvae  feed.  The  latter  are 
slender,  white,  worm-like  creat- 
ures, with  a  distinct  black  head,  and  usually  feed  together  in 
considerable  numbers.  They  sometimes  develop  a  curious  wan- 
dering habit  when  full-grown,  marching  in  rope-  or  ribbon-like 
aggregations  an  inch  or  two  wide  and  from  six  to  ten  inches 
in  length.  Some  bands  have  been  observed  from  four  to  five 
inches  wide  and  twelve  feet  in  length,  piled  up  from  four  to  six 
deep  !  Ordinarily  no  injury  is  done  by  these  insects,  which  are 
rather  scavengers  than  otherwise  ;  but  one  species  of  Sciara 
becomes  a  serious  pest  to  mushroom  growers,  eating  into  the 
plants  and  utterly  ruining  them.  In  fact,  in  many  localities  it 
is  simply  impossible  to  grow  mushrooms  after  warm  weather 
sets  in.  Measurable  exemption  may  be  secured  by  keeping  the 
houses  or  cellars  tightly  closed  and  fumigating  frequently  with 
tobacco  or  pyrethrum  to  kill  the  flies.  In  a  cellar  the  flies  al- 
ways get  to  any  window  or  other  source  of  light,  and  great  masses 
can  be  killed  in  such  situations  by  a  fine  spray  of  kerosene  emul- 
sion diluted  ten  times. 

Quite  recently  Mr.  Hopkins,  of  the  West  Virginia  Experiment 


Chii  onomus  species,  male,  enlarged. 


Till:     IXSECT    WORLD. 


335 


Station,  has  found  a  species  of  this  family  concerned  in  j)rochicing 
a  form  ol  potato  scab  in  that  State.      He  has  named  it  Epidapus 

Fig.  383. 


Sciara  tritici. — a.  larva;    b,  c.  pupa  from  below  and  side;    d,  female  fly;    e,/,  tips  of 
female  and  male  abdomen. 

scabci,  and  beheves  it  to  Ijc  responsible  for  much  of  the  injury 
usually  ascribed  to  the  germ  disease.      This  may  be   locally  true, 


Fig.  384. 


Epidapus  scabei. — Wingless  female  and  structural  details. 

but  I   have  never  found  any  trace  of  the  insect  in  New  Jersey, 
though  I  have  examined  many  hundreds  of  scabby  potatoes  for 


33^ 


AN   ECONOMIC  ENTOMOLOGY. 


Eggs   and   larva  of  Epidapus 
scabei,  much  enlarged. 


that  especial  purpose.  Fortunately,  the  measures  used  to  prevent 
the  scab  due  to  the  fungous  disease  seem  to  destroy  the  insects  as 
well  ;  hence  the  method  of  distinguishing 
between  the  two  is  not  important. 

In  the  family  CecidomyidcB,  containing 
the  midges,  or  "gall-gnats,"  we  find  the 
most  injurious  species  of  the  order.  They 
are  also  mosquito-like  in  appearance,  but 
usually  very  small,  with  very  long  an- 
tennse,  which  in  the  males  are  clothed  on 
each  joint  with  whorls  of  fine  hair.  The 
larvae  are  ovate,  quite  broad,  and  a  little 
flattened,  the  segments  well  marked,  and 
the  apparent  mouth  parts  formed  in 
many  species  by  a  peculiar  horny  pro- 
cess which  is  known  as  the  "breast- 
bone," from  its  situation.  The  species 
are  numerous,  and  the  larval  habits  and 
life  histories  are  very  diverse.  In  most 
cases  growing  vegetable  tissue  is  the 
food,  and,  as  a  rule,  a  more  or  less  marked  gall-like  swelling 
indicates  the  location  of  the  larva. 

The  most  widely  known  species  is  the  "Hessian-fly,"  Cecid- 
omyia  destructor,  one  of  the  most  serious  enemies  of  wheat, 
actually  inhibiting  its  cultivation  in  some  localities.  The  adult 
is  rather  large  for  this  family,  smoky  brown  in  color,  and  appears 
late  in  the  season,  usually  after  the  wheat  is  well  above  ground. 
Eggs  are  laid  on  the  young  plants,  and  the  larvae  work  their  w^ay 
into  the  stem  at  or  near  the  surface,  causing  a  slight  gall  or  swell- 
ing and  a  deformity  in  plant  growth.  When  winter  sets  in  full 
size  has  been  reached,  and  the  "flaxseed"  stage  is  entered 
upon, — so  called  because  of  its  superficial  appearance,  though  it 
is  really  the  brown,  dry,  and  hardened  larval  skin  itself.  In 
spring  the  pupa  is  formed,  and  soon  afterwards  the  adult  appears, 
ready  to  oviposit  again  in  the  now  rapidly  growing  wheat.  The 
flaxseed  stage  is  again  formed  low  down  in  the  stalk  before  har- 
vest, so  that  it  usually  remains  in  the  stubble  when  the  grain  is 
cut.  There  it  rests  until  the  new  wheat  sprouts  in  fall,  though 
flies  may  be  found  all  summer,  and  it  is  more  than  likely  that 


Fig.  3S6. 


The  Hessian-fly,  Cecidomyia  destynctor.—On  the  left  a  healthy  stalk  of  wheat,  and  on  the 
right  one  infested  at  li  by  Hossian-fly,  sho\vinjj;the  galls,  a,  egg;  b,  larva;  c,  "flaxseed;" 
d,  pupa,  all  very  much  enlarged  ;  e,  fly  ovipositing  on  leaf,  natural  size  ;  /,  female,  and  g, 
male  Hessian-fly,  much  enlarged  ;  :',  the  parasite,  Merims  destructor,  much  enlarged. 

22  337 


338 


AN  ECONOMIC  ENTOMOLOGY. 


certain  grasses  also  sustain  the  species  in  the  interval  between 
harvest  and  seeding. 

The  injury  is  done  by  stunting  and  aborting  the  wheat  plants 
in  the  fall,  and  in  dwarfing  stalks  in  the  spring  or  so  weaken- 
ing them  that  they  fall  or  ' '  lodge' '  readily,  preventing  thereby 
the  development  of  the  ' '  ear' '  or  of  the  grain  in  it. 

Insecticide  applications  are  hopeless,  and  modified  farm  practice 
is  the  only  satisfactory  measure  within  our  power.  Very  late  sow- 
ing in  the  fall — as  late  as  it  is  safe  to  do  so — will  force  the  insects  to 
oviposit  in  volunteer  shoots  or  grasses,  and  the  later  germinating 
crop  remains  exempt.  As  far  as  possible,  infested  stubble  should 
be  ploughed  under  deeply  immediately  after  harvest  to  destroy  a 
large  percentage  of  the  "  flaxseeds,"  or  it  should  be  burnt. 

Another,  related  pest,  is  the  "wheat-midge,"  Diplosis  tritici, 
which  in  the  larval  stage  feeds  upon  the  kernel  of  the  grain, 
dwarfing  it  or  causing  its  entire  abortion.  This  larva  is  quite 
red  in  color,  and  the  parent  midges  are  about  in  June,  oviposit- 
ing in  the  blossoms  or  on  very  young  kernels.  In  this  case 
also  deep  ploughing  after  harvest  is  advisable,  and  after  threshing 
all  chaff  should  be  disposed  of  so  as  to  destroy  all  chance  of  life 
for  such  insects  as  may  yet  be  in  it. 

The  "clover-seed-midge,"  Cecidomyia  leguminicola,  is  also  a 
dangerous  enemy  in  some  localities  where  seed  rather  than  hay 
or  fodder  is  desired.  The  midges  lay  their  eggs  in  the  flowers, 
and  the  resulting  larvae  feed  upon  the  forming  seed,  utterly  de- 
stroying it.  Where  the  insects  are  known  to  occur,  cutting  an 
early  crop  just  when  it  is  in  full  head  and  depending  upon  a  sec- 
ond crop  for  seed  is  good  practice.  The  midges  oviposit  in  the 
flowers  of  the  first  crop,  and  those  of  later  date  will  be  practically 
exempt.  The  cutting  can  be  high,  so  as  just  to  include  all  the 
heads,  which  will  be  rapidly  renewed  from  the  vigorous  stalks 
remaining.  Fall  ploughing  infested  fields  is  good  practice,  or 
ploughing  under  after  cutting,  and  planting  some  cultivated  crop 
that  involves  frequent  stirring  of  the  soil.  The  insects  winter 
just  below  the  surface  among  the  roots,  and  the  practice  above 
suggested  looks  towards  winter  killing  them.  A  liberal  use  of 
lime  and  kainit  after  the  crop  is  off  is  also  good  practice,  and 
will  kill  many  of  the  larvae  then  barely  beneath  the  surface  and 
not  yet  in  their  cocoons. 


THE    liXSECT    WORLD. 


339 


The  "  pear-midge,"  Diplosis  pyn'vora,  is  an  imported  species 
appearing  with  the  first  buds  of  early  spring  and  ovipositing  in 
them  as  soon  as  they  begin  to  show  white.  The  young  larvae 
make  their  way  to  the  ovary  or  seed-capsule  of  the  setting  fruit, 
and  when  this  reaches  the  size  of  a  nut,  growth  stops.  The  pears 
are  then  irregular  in  shape,  a  little  knotty,  and  filled  in  the  centre 
with  a  mass  of  orange-yellow  larv.ne.  In  June  these  become  full- 
grown,     leave     the 

pears, — which    now  ^^'^'-  ^^"• 

crack  open  and  de- 
cay,— and  drop  to 
the  ground,  beneath 
the  surface  of  w^hich 
they  pass  the  winter. 
The  insect  is  es- 
pecially fond  of  the 
' '  Lawrence' '  va- 
riety, and  where 
such  can  be  found 
in  sufficient  num- 
bers, all  others  are 
exempt.  The  way  in 
which  this  species 
can  be  controlled 
is  by  treating  the 
ground  beneath  in- 
fested trees  with  a 
heavy  top-dressing 
of  kainit, — say  one 
ton  to  the  acre, — appHed  between  the  middle  and  end  of  June. 
Planting  "Lawrence"  trees  as  traps  and  applying  the  above 
remedy  to  the  soil  beneath  them  will  decidedly  lessen  the  injury 
to  the  balance  of  the  orchard,  or  their  fruit  may  be  gathered 
and  destroyed  in  May,  with  all  the  contained  larvae. 

Not  all  the  gall-midges  are  injurious,  however.  Many  species 
form  galls  or  other  distortions  of  growth  on  weeds  or  other  plants 
of  no  special  economic  interest,  or  in  such  a  way  as  to  cause  no 
real  injury,  and  a  few  are  actually  predaceous  and  directly  bene- 
ficial.    Such  is  the  species  that  feeds  in  the  Phylloxera  leaf-galls 


The  pear-midge,  Diplosis  pyrivora. — a,  female  adult ; 
pupa  ;  other  references  are  to  structural  details. 


340 


AN  ECONOMIC  ENTOMOLOGY. 


Fig 


on  the  grape,  and  not  improbably  other  species  occasionally 
found  in  leaf-galls  are  predatory  upon  the  original  producer.  As 
a  whole,  the  gall-midges  are  to  be  regarded  as  dangerous,  and 
the  measures  to  be  adopted  against  them  are,  in  almost  all  im- 
portant cases,  modifications  of  farm  practice,  since  they  are  usu- 
ally beyond  the  reach  of  insecticide  substances. 

This  closes  the  series  of  long-horned,  mosquito-like  flies,  none 
of  which  are  of  direct  benefit  to  the  farmer,  while  not  a  few  are 
among  his  most  dangerous  foes.  As  a  whole,  the  species  should 
be  looked  upon  with  suspicion  and  closely  investigated  when 
they  occur  in  numbers  great  enough  to  attract  attention. 

Quite  early  in  the  season  we  may  see  large  numbers  of  loose- 
jointed,  ungainly  flies  of  moderate  size,  with  long,  stout  legs, 
heavy  body,  short,  stout,  though    many-jointed   antennae,   and 

often,  in  the  female,  a  ridic- 
ulously small  head.  In 
color  they  are  black,  or 
black  and  yellow,  or  red. 
These  belong  to  the  family 
BibionidcB^  sometimes 
called  ' '  March-flies, ' '  from 
their  early  appearance  ;  and 
while  their  larvae  are  some- 
times feeders  on  grass  roots, 
they  never  become  eco- 
nomically important.  They 
are  mentioned  here  because 
their  early  appearance  in 
great  numbers  sometimes  at- 
tracts attention.  They  are 
often  plentiful  in  orchards 
just  when  the  blossoms 
open,  but  seem  not  to  be 
of  any  service  in  poUen- 
izing. 
are  in  some  localities  serious  pests 
The  "black  flies"  of  the  North- 


Bibio  albipciniis.  —  a,  male;  c,  its  head;  b,  fe- 
male ;  rf,  her  head  ;  c,  f,  g,  other  structural 
details. 


"  Black  flies,"  or  "gnats," 
to  man  and  domestic  animals, 
ern  woods  and  the  "buffalo-"  and  "turkey-gnats"  of  the  South- 
ern and  Mississippi  States  are  good  examples.     They  are  rather 


THE    INSECT    WORLD. 


341 


undersized,  chunky  flies,  dark  in  color,  with  the  thorax  well 
developed  and  somewhat  produced  forward  so  as  to  partially 
conceal  the  small  head  from  above.  Though  the  head  is  small 
,in  proportion  to  the  insect,  the  mouth  parts  are  exceedingly 
well  developed  and  furnished 
with  a  formidable  array  of 
lancets  for  puncturing  and 
blood-sucking.  They  belong 
to  the  natural  family  Sinm- 
/iidce,  and  are  distinguished, 
in  addition  to  the  peculiari- 
ties enumerated  above,  by 
short,  broad  wings,  in  which 
the  venation  is  almost  obso- 
lete, except  along  the  front 
margin. 

The  larvae  are  curious  little 
creatures,  living  under  water 
in  rather  swiftly  flowing 
streams,  clinging  to  rocks, 
sticks,  or  logs,  and  feeding 
upon  vegetable  matter.  They 
are  furnished  with  sucker-like 
structures  at  both  extremities, 
by  means  of  which  they  cling 
to  their  resting-place,  and  move  from  place  to  place,  breathing 
by  means  of  tracheal  gills. 

In  favorable  localities  these  insects  may  develop  in  enormous 
numbers,  and,  flying  in  the  bright  light  of  mid-day,  attack  any 
warm-blooded  animal  that  comes  in  their  way.  Such  is  their 
number  sometimes  that  they  completely  cover  the  animal  at- 
tacked, first  rendering  it  frantic  by  the  pain  inflicted  and  soon 
after  weak  from  the  loss  of  blood.  Eventually  death  ensues, 
whether  the  animal  be  a  man  or  a  mule,  unless  repellents  are 
employed  or  a  rapid  retreat  out  of  the  infested  territory  is 
accomplished. 

Where  the  insects  breed  in  shallow  streams,  the  larvae  attached 
to  stones,  nothing  can  be  done  to  check  development,  and  the 
mixture  already  recommended  for  mosquitoes — viz.,  oil  of  tar, 


Buffalo-gnat. 


342 


AN  ECONOMIC   ENTOMOLOGY. 


Fig.  390. 


oil  of  pennyroyal,  and  sweet  oil — must  be  resorted  to  for  man, 
while  fish  oil,  with  an  admixture  of  crude  carbolic  acid  or  creo- 
sote, will  be  found  effective  for  animals.  Smudges  are  often 
used  where  buffalo-gnats  are  abundant,  and  the 
stock  soon  learn  that  in  or  near  the  smoke  ex- 
emption from  attack  may  be  secured.  Where 
„  the  water  of  infested  streams 

is  deep,  undue  multiplication 
is  frequently  chargeable  to  an 
accumulation  of  logs  or  other 

)|^|  ""^^^M^^^i^-^    material  at  certain  points,  af- 

"^S\  fy^^lhv^  fording   suitable   locations    for 

LSii=^  l(^j«M"*\  |.j^g  development  of  the  gnat 

larvae.  In  such  cases  much 
good  may  be  accomplished 
and  sometimes  practical  ex- 
emption may  be  secured  by 
cleaning  out  the  streams  and 
thus  destroying  the  breeding- 
places.  Stationary  rafts  of  logs 
should  not  be  allowed,  and  the 
surface  should  be  kept  as  free  as  possible  of  anything  to  which 
the  larvae  can  attach  themselves. 

The  "horse-flies,"  or  TabanidcE,  comprise  another  set  of 
troublesome  creatures,  of  medium  or  large  size.  They  have 
short,  broad  heads,  enormous  eyes,  and  short,  though  many- 
jointed,  feelers.  The  abdomen  is  oval,  a  little  flattened,  and  the 
body  is  convex  and  powerful.  The  mouth  parts  are  well 
developed,  consisting  of  a  series  of  five  sharp-pointed  lancets  so 
rigid  that  they  readily  pierce  the  skin  and  draw  blood  almost  as 
soon  as  they  touch.  These  flies  frequent  woods  or  the  edges  of 
woodland,  sometimes  low  meadows  or  marshy  places,  and  occa- 
sionally prove  serious  pests  to  stock.  They  are  often  trouble- 
some in  woody  roads,  because  with  three  or  four  of  the  large 
black  flies  buzzing  about,  horses  may  be  driven  almost  frantic. 
Similar  species  occur  in  great  numbers  along  the  sea-shore, 
where  they  are  known  as  "green-heads."  In  some  localities 
they  are  known  as  "deer-flies,"  and  some  are  called  "golden- 
eyed  flies,"   having  the  eyes  more  or  less   banded  or  striped 


Larva    of  buffalo 
gnat. 


Pupa  of  buffalo-gnat. 


THE    INSECT   WORLD. 


343 


with  metallic  yellow  or  brown.  The  female  only  has  the  blood- 
sucking habit,  the  males  feeding  usually  upon  pollen,  and  being, 
therefore,  rarely  noticed,  except  by  the  collector.  The  larva; 
are  elongated,  somewhat  flattened  creatures,  some  living  in  the 
soil,  some  in  water,  and  some  in  marshes,  preying  upon  what- 
ever comes  in  their  way.     In  this  stage  they  might  possibly  be 


Fig.  392. 


a  6 

Horse-fly,  Tabanus  atraius.—a,  larva  ;  b,  pupa  ;  c,  adult. 


reckoned  of  some  benefit,  did  they  inhabit  places  frequented  by 
injurious  insects  ;  but  at  best  they  are  harmless, — unlike  their 
parents  in  this  as  in  all  other  respects. 

Horses  driven  through  districts  badly  infested  by  these  insects 
should  be  furnished  with  a  netting,  and,  if  it  is  necessary  to  keep 
the  animals  for  any  time  exposed  to  attack,  the  fish  oil  and  car- 
bolic acid  mixture  already  recommended  can  be  used  to  repel 
the  flies.  It  need  be  applied  only  in  such  places  as  the  animal 
cannot  conveniently  reach  with  its  tail,  or  which  is  not  sheltered 
by  a  netting. 

Somewhat  resembling  "horse-flies"  in  appearance  are  the 
members  of  the  family  Stratiomyiidce,  or  "  soldier-flies,"  so  called 
because  of  their  often  bright  bandings  of  green  and  yellow. 
They  have  the  same  general  shape  but  rather  longer  antennae, 
with  broader,  much  more  flattened,  abdomen.  They  are  not 
troublesome  in  any  stage,  and  are  referred  to  simply  because  of 


344 


AiV  ECONOMIC   ENTOMOLOGY. 


Fig.  393. 


An    Asilid    fly. — Erax   bastardi 
larva,  pupa,  and  adult. 


their  resemblance  to,  and  to  distinguish  them  from,  the  "  horse- 
flies." 

Another  series  of  large  species  we  find  among  the  "robber- 
flies"  belonging  to  the  family  Asilidcz,  and  these  are  quite 
different  in  appearance  from  any  heretofore  treated.  The  head  is 
prominent,  very  hairy,  with  rather  short,  several-jointed  antennae, 

and  with  a  short,  stout  proboscis, 
which  is  formed  for  piercing.  The 
body  is  robust,  also  covered  with  hair, 
and  the  abdomen  is  long,  slender,  and 
cylindrical,  tapering  very  gradually  to 
the  tip.  The  wings  are  long  and  nar- 
row, the  legs  moderately  long  and  very 
powerful,  densely  clothed  with  spines, 
while  the  tips  of  the  tarsi  are  supplied 
with  unusually  long  and  stout  claws. 
The  insects  are  called  ' '  robber-flies' ' 
from  their  habit  of  pouncing  upon, 
piercing,  and  sucking  the  juices  of 
other  insects  in  mid-air,  while  holding 
them  with  their  powerful  legs.  We  have  a  great  variety  of 
species,  some  of  them  large  and  brightly  colored,  though  the 
majority  are  of  a  sober  gray,  varying  sometimes  to  reddish, 
sometimes  to  yellow,  and  only  rarely  becoming  black,  except  in 
the  genus  Laphria.  Though  predaceous,  the  insects  can  hardly 
be  called  beneficial,  because  they  rarely  attack  injurious  species, 
and  in  some  cases  become  themselves  injurious  by  attacking 
bees.  The  late  Dr.  C.  V.  Riley  records  having  observed  a  single 
species  kill  forty  bees  in  one  afternoon.  Professor  Comstock 
notes  their  feeding  upon  the  cotton-worm,  and  undoubtedly 
they  do  occasionally  kill  injurious  insects,  but  can  scarcely  be 
credited  with  being  a  factor  of  much  importance  in  keeping  down 
troublesome  forms.  They  never  attack  man  or  animals,  although, 
if  carelessly  handled,  they  are  ready  to  sink  their  lancets  into  the 
flesh  of  their  captor.  The  larvae  are  also  carnivorous,  so  far  as 
known,  and  live  in  the  ground  or  in  decaying  wood. 

Yet  larger  in  size  and  of  the  same  general  shape  are  the  mem- 
bers of  the  family  Midaidce.  They  are  often  contrastingly  col- 
ored, sometimes  uniformly  dead  black  or  blue,   though  usually 


THE    INSECT   WORLD.  345 

relieved  by  a  bright  red  or  yellow  band  or  similar  marking. 
The  wings  are  quite  generally  blackish  and  the  antennae  are 
clubbed  at  the  tip,  differing  thus  from  the  previous  family.  In 
fact,  the  species  are  so  peculiar  that,  having  been  once  seen,  they 
can  scarcely  be  mistaken.  They  are  also  predaceous  in  habit, 
but  not  nearly  so  ravenous  as  the  "  robber-flies,"  besides  being 
much  less  abundant. 

A  very  interesting  family  is  that  of  the  "  bee-flies,"  or  Bomby- 
liidce,  which  derive  their  common  name  from  the  fact  that  they 
are  more  or  less  covered  with  dense,  diverging,  whitish  or  yellow 
hair,  giving  them  a  close  resemblance  to  certain  bees.  Many  of 
the  species  occur  in  open  places,  hovering  over  bare  spots, 
especially  in  spring,  and  they  may  be  found  at  other  seasons 
flitting  from  flower  to  flower,  often  poised  in  mid-air  between  or 
over  them.  There  are  two  rather  distinct  series,  one  of  them 
with  robust  species  resembling  a  bumble-bee,  and  with  a  very 
long  tongue  ;  the  other  much  more  slender,  the  species  re- 
sembling flower-flies,  with  a  much  shorter  proboscis  and  much 
less  contrasting  colors.  The  former  are  typified  in  the  genus 
Bombylius :  the  latter  belong  to  Anthrax  and  allied  genera. 
Their  food  is  honey  obtained  from  flowers,  and  the  adults  are  at 
least  innoxious.  Among  the  species  that  occur  early  in  the  year, 
some  are  of  direct  benefit  in  the  orchard,  where  they  aid  in  pol- 
lenizing  fruit  flowers.  The  hairs  composing  the  vestiture  are 
furnished  with  little  spurs  or  processes,  or  are  twisted,  so  that 
pollen  grains  adhere  readily.  They  are  especially  useful  in 
cross-pollenation  from  their  habit  of  flying  considerable  distances. 
The  larvae,  on  the  other  hand,  are  parasites,  and  distinctly  bene- 
ficial in  many  instances.  They  prey  upon  the  larvae  of  Lepidop- 
tera,  including  many  of  the  cut-worms,  and  also  infest  the  egg- 
pods  of  grasshoppers,  forming  one  of  the  effective  checks  of  the 
migrating  or  "  Rocky  Mountain  locusts"  in  this  country.  They 
are  less  beneficial  when  parasitic  upon  bees  and  other  Hyme- 
noptera,  but  altogether  the  family  may  be  said  to  contain  chiefly 
useful  species. 

Sometimes  we  find  in  houses,  under  carpets,  a  slender  little 
larva  nearly  white  in  color,  with  a  darker,  rather  indistinct,  head, 
but  without  obvious  legs.  It  is  usually  looked  upon  with  sus- 
picion because  of  the  locality  in  which  it  is  found,  but  as  a  matter 


346 


AN'  ECONOMIC  ENTOMOLOGY. 
Fig.  :,94. 


CL^ 


^■■\   .     ,.--*«*- 


i  H-  ^ 


Fig.  395. 


Fig.  396. 


Bee-flies. — Fig.  394,  Aiit/irax  hypomelas :  a,  larva;  b,  the  fly  pupa  projecting  from  a 
cut-worm  pupa  ;  c,  pupa  ;  d,  adult.  Fig.  395,  larva,  with  details,  of  Systcechus  oreas, 
parasitic  in  grasshopper  egg-pods.    Fig.  396,  pupa  and  adult  of  Systcechus  oreas. 


THE    INSECT   WORLD. 


347 


Scenopiiius  ffnestvalis. 


of  fact  it  is  predaceous  in  habit,  and  feeds  upon  the  species 
really  infesting  carpets  and  similar  material.  Thus,  ' '  moths, ' ' 
the  larva;  of  the  "carpet-beetle,"  "fish-moths,"  and  numerous 
other  insects   likely  to 

occur    in     such     situa-  ^''^-  •^97- 

tions  are  destroyed  by 
it.  From  this  larva 
there  comes  in  due 
time  a  small  blue  fly, 
a  member  of  the  family 
ScenopinidcB^  slender 
and  somewhat  flattened 
in  appearance,  with  yel- 
low or  reddish  legs,  and 
this  may  be  sometimes 
seen  upon  the  win- 
dows.      These     larvae 

have  been  often  brought  to  me,  and  the  little  flies  raised  from 
them  hax'e  always  been  Scenopinvs  fenestralis,  from  which  Pro- 
fessor Comstock  gives  the  group  the  name  "window-flies." 

The  remainder  of  the  Diptcra  have  the  antennae  short,  rarely 
more  than  three-jointed,  and  usually  with  a  bristle  or  style,  called 
an  "arista,"  which  may  or  may  not  be  feathered  or  plumose, 
from  the  second  or  third  joint.  The  first  of  the  families  to  which 
it  is  necessary  to  refer  here  is  the  Syrphidce,  containing  a  large 
number  of  species,  most  of  them  prettily  colored,  yellow,  black, 
or  bronze,  patterned  and  marked  in  many  different  ways.  They 
frequent  flowers,  hovering  and  often  remaining  suspended  over 
them  in  mid-air  for  some  time,  then  suddenly  darting  away  and 
again  returning.  Their  habits  and  appearance  frequently  give 
them  a  resemblance  to  bees  and  wasps,  and  in  some  species  this 
is  carried  so  far  that  they  are  easily  mistaken  for  members  of  the 
order  Hymenoptera  by  those  not  familiar  with  them.  As  a  rule, 
the  head  is  quite  large,  the  body  barrel-shaped,  and  the  abdomen 
a  little  flattened,  varying  from  very  slender  to  broadly  oval  in 
shape.  This  abdomen  is  yellow  and  black,  or  bronze  banded, 
sometimes  entirely  bronzed,  more  rarely  blue  or  green,  but 
nearly  always  brightly  colored  in  some  way.  Some  of  the  flies 
have  the  body  distinctly  covered  with  hair,  though  generally  this 


348 


AN  ECONOMIC  ENTOMOLOGY. 


Fig.  399. 


vestiture  is  confined  to  the  thorax  or  trunk,  and  such  species  are 
sometimes  of  use  in  pollenizing  flowers.  I  have  found  several 
species  about  fruit-blossoms  in  spring,  moving  from  flower  to 
flower,  and,  adhering  to  the  vestiture,  I  have  found  pollen  grains 
in  considerable  number  ;  so  the  insects  are  probably  of  some 
importance  in  this  direction.  We  have  one  very  large  species, 
Eristalis  ienax,  appearing  late  in  fall,  often  in  houses,  and  so 
closely  resembling  a  honey-bee  as  to  be  generally  mistaken  for 
one  ;  for  which  reason  it  has  been  called  the  "  drone-fly."  It  is 
frequent  in  greenhouses  about  the  time 
that  chrysanthemums  are  in  bloom,  and 
gardeners  have  assured  me  that  pollen- 
izing this  flower  is  done  by  it  entirely  ; 
hence  they  call  it  ' '  chrysanthemum 
fly."  It  is  not  at  all  unlikely  that  this 
is  the  case  ;  indeed,  it  is  even  proba- 
ble, though  sufficiently  direct  observa- 
tions have  not  as  yet  been  made  in  the 
matter.  In  this  connection  it  is  inter- 
esting to  find  that  the  body  vestiture 
of  the  Syrphids  is  often  composed  of 
spurred  and  branched  hair,  similar  to 
that  found  in  bees,  and  in  the  "drone- 
fly'  '  this  character  is  especially  marked. 
As  widely  divergent  as  the  flies 
themselves  are  the  larvae  and  their 
feeding  habits.  In  fact,  there  is  no  sort 
of  agreement ;  and  while  some  are  pre- 
daceous,  feeding  upon  plant-lice  or 
other  insects,  many  feed  in  living  or 
decaying  vegetable  substances,  or  in 
the  foulest  excrementitious  material. 
Those  forms  that  most  concern  the  agri- 
culturist are  the  feeders  on  plant-lice, 
and  these  may  be  found  at  almost  any 
time  during  the  summer  in  almost  every 
aphid  colony,  busily  engaged  in  lessening  its  numbers.  The 
larvae  are  easily  overlooked,  as  they  are  usually  green  or  yel- 
lowish in  color,  like  the  insects  among  which  they  feed.     They 


y<Z-^ 


Body  vestiture  of  Eristalis 
tenax :  a,  entire  hair;  d,  c,  d, 
parts  of  same  ;  all  greatly  en- 
larged. 


Fig.   w^. 


Uee-flies  and  flower-flies. — a.  Hoiiibylius  sp. :  b.  h'oinbylius  sp.';  c.  Anthrax  sp.  ;  d, 
Kiistalis  lyansvnsus :  c,  Eiistalis  Irnax ;/,  Eristalis  saxorum ; g,  Syritta pipiens.  Some- 
wlial  enlarged.     From  a  photoi;ra])li. 


THE    INSECT   irOR/.D.  349 

are  wrinkled  and  hairy  when  examined  with  a  magnifying  glass, 
soft  in  texture,  thickened  behind,  and  tapering  almost  to  a  point 
at  the  head,  which  is  marked  only  by  a  pair  of  hooks  and  a 
little  circular  opening  representing  the  mouth.  They  have  no 
legs,  and  move  by  extending  the  body  forward  as  far  as  pos- 
sible, then  clinging  with  the  anterior  segments  to  the  leaf  or 
twig,  and  drawing  the  balance  to  meet  the  head.  Awkwardly 
as  they  move,  however,  their  progress  is  yet  sufficiently  rapid 
for  their  purpose.  When  once  a  larva  has  established  itself  in 
a  colony  of  plant-lice,  it  never  stirs  until  all  in  its  immediate 
vicinity  are  destroyed  ;  it  then  moves  only  far  enough  to  bring 
into  reach  additional  prey,  and  so  continues  until  no  more  re- 
main. The  female  lays  her  eggs  close  to,  or  actually  among, 
an  aphid  colony,  so  that  the  larva  finds  food  ready  at  hand 
as  soon  as  it  is  hatched.  It  grasps  a  plant-louse  with  the 
mouth  parts,  lifts  it  from  the  surface,  and  sucks 
its  juices,  leaving  the  creature  to  struggle  for  'J^ 

a  time,  helplessly  kicking  its  legs  in  mid-air. 
When  the  juices  are  exhausted  the  empty  shell 
is  dropped  and  another  specimen  is  taken. 
When  full-grown,  the  larva  draws  itself  up 
into  a  humped  mass  ;  the  outer  skin  hardens,  syiphus  larva  de- 
darkens  in  color,  and  forms  an  apparently  solid     ^ounng    a    piant- 

1         1  •    1       1  louse. 

covering  or  coarctate  pupa,  beneath  which  the 
true  or  soft  pupa  of  the  fly  is  formed.     Several  broods  of  these 
predaceous  flies  occur  in  the  course  of  the  season,  and  they  are 
among   the   most    important    checks  that    nature   has   provided 
against  plant-lice  increase. 

Others  of  the  species  are  not  quite  so  useful,  and  occasionally 
we  have  a  form  that  is  almost  parasitic,  living  in  nests  of  bum- 
ble-bees or  other  Hymenopterous  insects  and  feeding  upon 
their  larvae.  In  such  cases  we  often  find  that  the  flies  greatly 
resemble  in  appearance  the  hosts  among  which  they  live. 
Among  the  feeders  in  vegetable  matter  we  have  a  great  variety 
of  form,  but  they  are  usually  more  or  less  maggot-like  and 
without  legs.  As  they  are  not  of  particular  economic  interest, 
no  more  attention  need  be  paid  them  here.  The  larva  of  the 
"drone-"  or  "chrysanthemum-fly,"  Eristalis  teiiax,  lives  in 
ijiasses  of  soft,  decaying,  or  excrementitious  matter.     It  is  fre- 


35° 


AN  ECONOMIC  ENTOMOLOGY. 


quently  found  in  privies  or  cesspools,  sometimes  appearing  so 
suddenly  and  in  such  numbers  that  a  suspicion  is  engendered 
that  the  specimens  have  been  passed  by  the  individuals  using  the 
out-house.  In  fact,  I  have  on  more  than  one  occasion  received 
the  larvae  with  the  positive  statement  that  this  had  actually 
occurred.  They  are  curious  creatures,  maggot-like  in  general 
shape,  with  a  long,  extensile,  tail-like  appendage  at  the  anal  ex- 
tremity. It  is  hollow  or  tube-like,  and  at  the  end  is  a  spiracle, 
the  use  of  this  telescopic  tail  being  simply  to  keep  the  opening 
above  the  surface  of  the  filthy  mass  in  which  the  insect  lives,  and 
thus  to  secure  a  supply  of  pure  air.  The 
larvae  are  called  from  this  peculiarity  ' '  rat- 
tailed."  The  reason  why  the  flies  are 
sometimes  so  abundant  in  greenhouses  is 
that  somewhere  in  their  vicinity,  among 
semi-liquid  manure,  the  best  breeding- 
places  can  usually  be  found.  Taken  as  a 
whole,  this  family  SyrphidcE  contains  no  really  noxious  insects, 
and  many  that  are  decidedly  beneficial.  It  should  be  noted, 
however,  that  the  larvae  of  some  species  feed  upon  pollen,  and 
that  others  live  in  growing  vegetable  tissue  ;  hence  it  is  not 
impossible  that  in  the  future  this  general  statement  may  have  to 

Fig.  402. 


Fig.  401. 


Rat-tailed  X-Axvz-oi Etistalis. 


Mesograpta  poh/a.—L.a.rva,  pupa,  and  adult;  all  enlarged. 


be  modified.  One  of  the  most  common  Eastern  species,  Meso- 
grapta polita^  has  been  found  feeding  in  great  numbers  in  the 
larval  stage  upon  corn  pollen,  but  without  causing  any  real  injury. 
Passing  over  several  small  families  interesting  enough  in  them- 
selves, but  not  of  importance  to  the  agriculturist,  we  reach  the 


THE    INSECT   WORLD. 


351 


little  family  Conopidic,  which  is  not  at  all  injurious,  but  rather 
the  contrary.  Professor  Comstock  calls  them  "thick-head  flies," 
and  the  term  is  not  bad,  because  the  head  is  usually  very  promi- 
nent and  as  wide  or  wider  than  the  body.  The  thorax  is  unusu- 
ally short,  and  bears  a  long  abdomen  having  the 
basal  joints  very  slender  and  the  terminal  joints  Fig.  403. 

enlarged,  bulb-like,  much  resembling  in  appear- 
ance that  of  certain  wasps.  The  flies  are  moder- 
ate in  size,  with  the  wings  more  or  less  brown  or 
clouded,  and  they  may  often  be  found  on  flowers 
after  midsummer,  in  company  with  the  Hymen-        _     .  ,  ^    , 

^  I-        J  J  Conops  ttbialts. 

optera,  which  they  resemble.  The  larvae  are 
parasites,  chiefly,  it  is  said,  upon  bumble-bees  and  wasps,  in 
which  case  they  are  not  beneficial  ;  but  also  on  grasshoppers,  in 
which  respect  they  deserve  our  most  distinguished  consideration. 
Distinctly  injurious  insects  we  find  in  the  family  CEstridce,  or 
"bot-flies."  These  are  usually  of  good  size,  sometimes  even 
very  large,  and  peculiar  by  having  the  mouth  parts  almost 
entirely  aborted.  Some  of  the  species  are  very  hairy,  yellowish 
in  color,  and  with  rather  a  pointed  abdomen  ;  while  others  are 
very  plump,  robust  flies,  blue  or  blue-black  in  color,  often  with 
a  whitish  bloom  like  that  of  a  plum,  formidable  in  appearance, 
though  in  fact  entirely  inoffensive  in  this  stage.  In  the  larval 
condition  they  are  known  as  "bots,"  and  live  beneath  the  skin, 
in  the  intestines,  or  in  the  mucus-lined  head  passages  of  the 
animals  infested  by  them.  Thus,  the  "horse-bot,"  Gast7'ophihis 
equi,  passes  its  life  in  the  stomach,  attached  to  the  inner  coat,  and 
there  remains  until  full  grown,  when  it  releases  its  hold  and  is 
passed  in  the  natural  way  through  the  anus.  It  then  crawls  into 
some  convenient  place  just  below  the  surface  of  the  ground,  or 
even  among  rubbish  on  top  of  it,  and  changes  to  a  pupa.  The 
adult  lays  its  eggs  on  the  hair,  chiefly  of  the  forelegs,  at  points 
easily  reached  by  the  tongue  of  the  animal  in  licking  itself.  The 
eggs  are  thus  removed,  carried  into  the  mouth  on  the  tongue, 
and  so  into  the  stomach,  where  the  larvae  hatch  almost  immedi- 
ately and  at  once  attach  themselves.  It  is  readily  seen  that  this 
habit  gives  us  a  certain  possibility  of  controlling  the  insects, 
because  if  the  horses  can  be  prevented  from  licking  ofl"  the  eggs, 
they   never  can   reach    the   proper   location   for    their  growth. 


352  AJV  ECONOMIC  ENTOMOLOGY. 

Checking  the  animals  up  when  in  use  accompHshes  this,  and  a 
spiked  muzzle,  so  arranged  as  not  to  interfere  with  feeding,  will 
answer  in  the  stable.  Frequent  brushing  to  remove  the  eggs  is 
useful  in  bot-infested  regions,  and  lessens  the  number  that  can 
reach  the  alimentary  canal. 

Numerous  other  species  occur  just  under  the  skin  of  the 
animals  infested,  and  one  of  the  best  known  of  these  is  the  "  ox 
warble,"  Hypoderma  lineata.  Here  also  the  eggs  are  laid  on 
the  hair  and  are  licked  off  in  the  same  way  ;  but  the  larvae,  instead 
of  allowing  themselves  to  be  carried  into  the  stomach,  pierce  the 
oesophagus  or  other  portion  of  the  alimentary  canal,  and  work 
their  way  through  the  muscular  tissue  to  a  point  just  below  the 
skin.  There  they  fix  and  increase  in  size,  causing  the  swelling 
and  suppuration  so  familiar  to  farmers  in  some  localities.  Of 
course  the  means  just  mentioned  for  preventing  the  entrance  of 
stomach  bots  are  also  applicable  in  this  case  to  avoid  infestation. 
Where  bots  are  already  established  on  an  animal,  the  best  method 
is  to  incise  the  skin  and  press  out  the  larva  beneath  it,  or  use  a 
mercurial  ointment,  which,  penetrating  into  the  wound,  will  kill 
the  larva,  so  that  it  can  be  readily  pressed  out  later,  or  will  sup- 
purate out  easily.  Some  species  of  bot-flies  undoubtedly  lay 
their  eggs  on  the  skin  of  the  animals  at  the  points  where  the 
larvae  actually  hatch,  and  the  latter  work  their  way  through  just 
there  and  form  the  swelling.  Sometimes  special  organs  are 
attacked,  as  in  the  chipmunks  and  squirrels,  where  the  testes  of 
the  males  are  selected  and  the  creatures  are  actually  emasculated. 
The  fly  has,  therefore,  been  called  the  "  emasculating  bot,"  Cuter- 
ebra  emascidator.  In  rabbits  a  species  is  found  close  to  the 
anal  opening,  and  in  fact  most  animals  are  more  or  less  subject 
to  bot  attack.  Even  man  is  not  exempt,  and  several  cases  have 
come  under  my  observation  where  flies  had  laid  their  eggs  on  the 
skin  and  the  bots  had  developed  considerably  before  the  charac- 
ter of  the  trouble  was  understood.  In  southern  countries  this  is 
much  more  likely  to  occur  than  in  the  north,  possibly  because  a 
much  greater  part  of  the  body  is  there  habitually  exposed. 

Sheep  suffer  from  a  species  known  as  CEstrus  ovis,  which  lays 
its  eggs  on  or  in  the  nostrils.  The  larvae  make  their  way  through 
the  nasal  passages  in  the  mucus  beneath  the  skin,  and  even  into 
the  horns.      They  are  often   very  troublesome,   and  cause  one 


THE    IXSECT    WORLD. 


353 


form  of  the  disease  known  as  "staggers,"  which  is  sometimes 
extremely  destructive  to  herds. 

From  this  description  of  the  Hfc  histories,  so  briefly  given,  it 
appears  that  our  efforts  to  avoid  injury  must  follow  in  the  direc- 
tion of  prevention.  As  against  the  species  that  must  first  be 
taken  into  the  mouth,  the  mechanical  ways  of  preventing  a 
horse  or  an  ox  from  licking  any  part  of  the  body  will  prove  suffi- 
cient ;  or  frequent  brush- 
ing will  at  least  moderate  I'^it"--  409- 
the  injury. 

In  the  case  of  the 
sheep-bot  the  matter  is 
more  difficult,  because  the 
flies  are  very  persistent, 
and  encircle  the  animals 
until  they  get  an  oppor- 
tunity to  dart  to  the  nos- 
tril and  deposit  upon  it 
an  &^^  just  ready  to 
hatch,  or  already  hatched, 
so  that  either  immedi- 
ately or  in  a  very  short 
time  the    maggot    makes 

its  way  up  along  the  mucous  membrane  as  far  as  the  passages 
allow  it  to  extend.  All  sorts  of  devices  have  been  adopted  to 
prevent  this,  but  none  are  entirely  satisfactory.  Tar  has  been 
used  as  a  repellent,  smeared  on  the  nose,  and  .vith  more  or  less 
success.  It  is  probable  that  fish  oil  and  oil  of  tar,  or  carbolic 
acid,  would  answer  the  same  purpose.  Powdered  tobacco,  used 
to  induce  the  sheep  to  sneeze  and  thus  dislodge  any  maggots 
that  had  already  made  their  way  in,  has  also  been  more  or  less 
satisfactory.  In  the  case  of  recently  infested  animals,  a  brush 
dipped  in  turpentine  and  carefully  used  in  the  nostrils,  so  as  to 
reach  attached  larvae  and  kill  them,  is  sometimes  found  useful. 

The  family  Muscidce  is  the  largest  in  number  of  genera  and 
species  in  the  order  as  well  as  the  most  difficult  to  classify.  The 
common  "house-fly,"  the  "  blue-bottle,"  and  the  "flesh-fly" 
are  examples,  and  may  be  considered  as  typical  forms,  which 
most  of  the  species  resemble  ;  not  necessarily  in  color  or  mark- 

23 


The  sheep-bot,  CEstius  ovis.  —  i,  2,  flies  ;  3,  pupa  ; 
4,  5,  full-grown  larva  ;  6,  young  larva. 


354 


AN  ECONOMIC  ENTOMOLOGY. 


ings,  but  in  general  type  of  structure.  It  is  almost  impossible 
for  any  but  the  special  student  to  distinguish  between  even  the 
sub-families,  and  yet  these  differ  greatly  in  habit,  some  being 
decidedly  injurious  and  others  as  decidedly  beneficial  in  the 
larval  stages.  One  of  the  peculiarities  of  all  the  members  is  very 
short  antennae,  in  which  the  terminal  joint  is  long  and  stout  and 
furnished  with  a  bristle  or  arista  attached  near  the  base.  The 
modifications  of  this  bristle  aid  in  distinguishing  the  groups. 

The  Tachina  flies,  for  instance,  have  the  bristle  entirely  bare, 
though  otherwise  many  of  them  resemble  the  common  "flesh- 
fly"  or  the  "blue-bottle."  They  are  generally  rather  large, 
robust  in  appearance,  always  bristly,  and  sometimes  formidable 
looking  from  the  array  of  sharp  spiny  points  projecting  in  every 
direction.  They  are  parasitic  in  habit,  largely  upon  caterpillars, 
and  among  them  perhaps  preferably  upon  cut-worms.  Fre- 
quently, where  the  latter  are  numerous,  a  large  percentage  will 
be  noticed  with  one  or  several  little  white  eggs  attached  on  the 
anterior  segments,  just  back  of  the  head,  in  such  a  position  that  the 
larvae  cannot  possibly  reach  or  destroy  them.  These  eggs  hatch 
in  a  very  short  time  into  little  maggot-like  creatures  that  at  once 
bore  through  the  skin  of  the  caterpillar  and  live  within  its  body, 
feeding  upon  the  fatty  masses  and  muscular  tissue  not  absolutely 
necessary  to  life.  When  the  maggots  are  full-grown  and  the 
welfare  of  the  caterpillar  is  no  longer  a  matter  of  importance  to 
them,  they  feed  on  regardless  of  consequences,  and  the  creature 
dies.  The  maggots,  sometimes  without  even  attempting  to  get 
out  of  their  host,  then  change  to  barrel-shaped  pupae.  This  is 
accomplished  by  a  contraction  of  the  larval  skin,  which  hardens 
and  becomes  brown  in  color,  releasing  its  hold  at  the  same  time 
on  the  forming  (true)  pupa  beneath.  Occasionally  the  maggots 
leave  their  host  and  make  their  way  a  little  below  ground  to 
pupate.  Some  of  our  large  caterpillars  attain  their  full  growth 
with  as  many  as  thirty  or  even  more  of  these  maggots  feeding 
upon  their  vitals.  Some  of  the  flies  are  very  handsome  and 
strikingly  colored,  as,  for  instance,  the  Tachina  vivida,  in  which 
the  abdomen  is  bright  red,  set  with  black  spines, — a  very  remark- 
able looking  species.  Others  are  black,  the  abdomen  banded 
with  yellow  ;  but  as  a  rule  they  are  of  a  modest  gray  color,  the 
thorax  rather  obscurely  streaked  with  blackish  brown  or  gray. 


Fic.  413. 


JrlG.  410. 


Muscid  flies. — Fig.  \\o,  Exorista  flavicauda,  yellow-tailed  Tachinid.  Fig.  411,  Ne- 
morea  leucanicE,  Tachinid  on  cut-worms:  larva,  pupa,  adult,  and  the  white  eggs  on 
the  anterior  segments  of  the  caterpillar.  Fig.  412,  Lydella  doryphoree ,  Tachinid  on 
potato-beetle.  Fig.  413,  common  flesh-fly,  Sarcophat^a  carnaria.  Fig.  414,  the  blow- 
fly, Calliphora  vomitoria.  Fig.  415,  screw-worm,  Lucilia  macellaria  :  a,  6,  c,  larva  and 
details;  rf,  pupa  ;  <?,  adult ;  /,  head  from  side.  All  are  enlarged,  and  Fig.  413  very 
much  so. 

355 


356  AN   ECONOMIC   ENTOMOLOGY. 

These  flies  are  among  the  most  effective  of  nature's  checks  to 
caterpillars,  especially  cut-worms. 

The  "flesh-flies"  greatly  resemble  the  Tachina  flies  in  ap- 
pearance, but  the  arista  or  bristle  of  the  antennae  is  feathered 
towards  the  base  and  is  bare  only  at  the  tip.  Some  of  these 
species  also  are  parasitic.  Others  have  larvae  that  live  in  excre 
mentitious  material,  in  fruits,  in  meats,  or  in  decaying  animal  or 
vegetable  matter  generally.  Such  species  usually  produce  their 
young  alive,  or  at  least  as  eggs  just  ready  to  hatch,  and  the 
majority  are  scavengers.  None  of  the  members  of  this  family,  so 
far  as  I  am  aware,  are  injurious,  and  they  are  always  beneficial  to 
the  extent,  at  least,  of  assisting  in  the  removal  of  offensive  matter, 
animal  or  vegetable. 

The  typical  Muscids  differ  from  the  other  species  in  this  series 
by  lacking  the  spines  of  the  thorax  and  abdomen,  or  having  them 
confined,  in  a  very  reduced  state,  to  the  tip  of  the  abdomen  only. 
The  arista  or  antennal  bristle  is  feathered  to  the  tip.  The  house- 
fly is  one  of  the  best  known  of  all  insects  the  world  over,  and 
there  seems  to  be  no  region  where  it  does  not  occur  and  is  not 
more  or  less  annoying.  It  winters  in  our  houses  or  out-buildings, 
hiding  in  some  sheltered  spot  in  cellar  or  attic,  or  remaining 
more  or  less  active  in  our  carefully  warmed  rooms.  During  the 
early  days  of  spring  a  few  specimens  make  their  appearance  here 
and  there,  sole  survivors  of  the  swarms  of  the  preceding  year. 
These  are  mostly  females  ready  to  reproduce,  and  they  lay  their 
eggs  in  any  convenient  pile  of  horse  manure  ;  or,  if  that  is  not 
available,  in  any  decaying  animal  or  vegetable  matter.  The 
maggots  hatch  in  a  day  or  two,  in  a  week  or  ten  days  are  full- 
grown,  change  to  pupae,  and  in  a  very  few  days  more  a  new 
brood  of  flies  is  matured,  already  sufficient  in  numbers  to  become 
more  or  less  annoying.  This  process  is  repeated  time  and  again 
during  the  season,  and  the  insects  increase  in  numbers  until  after 
midsummer,  when  they  seem  to  lose  activity  to  some  extent, 
although  breeding  until  cold  weather  actually  sets  in.  House- 
flies  are  not  injurious  in  any  true  sense  of  the  word,  although  they 
are  distinctly  annoying  and  may  become  dangerous  by  trans- 
ferring disease  germs  from  one  point  to  another  ;  as  when,  after 
alighting  and  feeding  upon  the  sputum  of  a  consumptive,  they 
tickle  the  nose  of  a  healthy  sleeper  a  few  minutes  thereafter.     So 


THE    INSECT   WORLD.  357 

blood  poisoning  may  be  set  up  by  a  fly  which  has  been  feechng 
upon  a  putrefying  carcass  and  then  feeds  upon  an  abraded  sur- 
face or  a  cut  or  bruise  on  man.  This,  however,  is  not  a  common 
occurrence,  and  perhaps  as  a  scavenger  the  insect  is  about  as 
useful  as  it  is  annoying.  A  single  female  produces  on  an  average 
about  one  hundred  and  fifty  eggs,  and  this,  with  the  short  period 
required  to  bring  them  to  maturity,  accounts  for  the  enormous 
increase  of  the  insects.  After  a  fly  has  attained  this  stage  it 
never  grows  more,  and  a  small  fly  never  makes  a  large  fly,  any 
more  than  the  progeny  of  a  large  fly  is  ever  a  small  fly. 

The  "blow-fly,"  Calliphora  voinitoria,  is  the  largest  of  the 
common  species  abundant  enough  to  attract  attention,  and  this 
has  the  body  of  a  deep  blue,  almost  black,  color,  the  abdomen  a 
little  lighter  and  somewhat  more  shining.  It  is  an  obtrusive 
creature  and  noisy  withal,  especially  when  flying  about  on  the 
windows  or  bumping  against  the  ceilings  of  a  room,  making  its 
presence  obnoxious  in  more  ways  than  one.  Its  eggs  are  laid  on 
all  sorts  of  animal  and  vegetable  matter  in  an  incipient  stage  of 
decay.  Meat  exposed  in  summer  is  almost  certain  to  show,  in  a 
very  short  time,  little  piles  of  elongate  white  eggs  scattered  over 
the  surface  here  and  there.  Fish  are  especially  subject  to  attack, 
and  I  have  myself  had  the  experience  that  a  little  string  of  fish 
laid  in  the  shade  of  a  bush  on  the  bank  was  covered  with  such 
eggs  before  I  was  ready  to  go  home.  Of  course  they  could  be 
readily  washed  off,  and  it  is  not  usual  for  this  insect  to  retain  the 
eggs  until  they  hatch  within  the  abdomen,  yet  I  have  found 
specimens  that  have  done  so.  This  species  also  requires  but  a 
very  short  period  for  its  development,  and  its  rate  of  increase  is 
so  great  that  it  has  given  rise  to  the  saying  that  a  pair  of  flies 
will  devour  an  ox  more  rapidly  than  will  a  lion.  A  carcass  left  in 
the  fields  during  midsummer  becomes,  in  fact,  in  a  few  days  a 
mass  of  maggots,  which  soon  leave  nothing  but  hide  and  bones. 

A  somewhat  smaller  species  than  this  blow-fly,  of  a  very  much 
brighter  green  or  bluish  color,  with  four  longitudinal  lines  on  the 
thorax,  is  the  "screw-worm"  fly,  Lticilia  macellaria.  This  is  a 
common  species  throughout  a  large  portion  of  our  country,  and 
ordinarily  feeds  upon  dead  or  decaying  animal  matter.  Under 
some  circumstances,  however,  it  attacks  living  animals,  and  in 
the  Southern  and  Southwestern  States  occasionally  becomes  a 


358  AN  ECONOMIC   ENTOMOLOGY. 

terrible  pest.  On  such  occasions  it  lays  its  eggs  on  man  or 
animals  wherever  there  is  the  slightest  trace  of  a  wound,  bruise, 
or  offensive  discharge  of  any  kind.  The  larvae  bore  directly  into 
the  living  flesh,  causing  intense  pain  as  well  as  suppurating  sores. 
Living  larvae  are  produced  as  well  as  eggs  almost  ready  to  hatch, 
and  into  any  opening  from  which  there  is  a  discharge  of  any 
kind  eggs  may  be  deposited.  Sleeping  humans  with  an  offen- 
sive breath,  or  with  a  fetid  discharge  from  the  nostrils  or  mouth, 
have  had  eggs  laid  at  theSe  points,  and  larvae  have  made  their  way 
into  the  head,  in  some  cases  causing  the  death  of  the  individual. 
Eggs  have  also  been  laid  in  the  ears  of  uncleanly  people,  and  the 
channels  and  passages  of  this  organ  have  been  penetrated  into  the 
head  and  destroyed.  Animals  are  troubled  in  the  same  way,  and 
where  the  insects  are  abundant,  their  attacks  often  become  fatal. 
The  only  remedy  is  cleanliness.  Wounds,  even  of  the  most 
trifling  nature,  on  cattle  should  be  smeared  with  an  antiseptic 
ointment.  As  far  as  possible,  all  materials  in  which  the  flies  can 
breed  should  be  destroyed  ;  no  accumulation  of  animal  refuse 
should  be  allowed  under  any  circumstances,  and  by  strictest  at- 
tention to  surroundings,  the  breeding  of  the  insects  should  be 
prevented.  Attacking  live  animals  is  not  a  usual  habit,  although 
very  readily  assumed  when  the  insects  become  abundant. 

Another  insect,  a  trifle  larger  than  the  house-fly  and  much 
like  it  in  appearance,  though  a  little  more  robust,  is  the  ordinary 
stable-fly,  Stomoxys  calcitrans.  This  has  the  mouth  parts  formed 
for  piercing,  and  annoys  animals  by  alighting  upon  and  sucking 
the  blood  of  parts  that  cannot  be  reached  by  them  with  head  or 
tail.  Sometimes  these  insects  also  attack  man,  especially  late  in 
the  season  or  in  heavy  weather.  They  have  an  especial  fondness 
for  human  shanks,  and  readily  bite  through  stockings  ;  sometimes 
through  trousers  as  well.  This  bite  is  painful,  though  it  rarely 
leaves  a  swelling  or  perceptible  inflammation.  The  larvae  develop 
in  horse  and  cow  manure,  and  their  increase  in  stables  can,  there- 
fore, be  checked  to  some  extent  by  promptly  removing  and 
placing  this  in  pits,  or  mixing  with  plaster  or  other  material  that 
will  absorb  the  moisture  and  fix  the  ammonia. 

A  close  ally  of  the  stable-fly  is  the  so  called  "horn-fly," 
Hcematobia  serrata,  a  recent  introduction  into  the  United  States, 
which  has  spread    over  the    country  with  almost    phenomenal 


THE    INSECT   WORLD. 


359 


rapidity.     This  insect  derives  its  common    name  from  the  fact 
that  it  seems  to  prefer  clustering  in  great  numbers  at  the  base  of 


Fig 


Horn-fly, 


Hamatobia   seriata. — a,   egg;  b,   fly; 
enlarged. 


(-  and  d,  head  and   mouth   parts ;  all 


Fig.  417. 


the  horns  of  cattle,  although  it  is  really  just  as  abundant  on  the 
flanks,  upon  the  udder,  and  in  other  places  where  it  cannot  be 
readily  reached  by  the  animals.  The  fly  seems  to  confine  its  at- 
tacks to  horned  cattle,  although  it  has  been  seen  on  mules  in  the 
State  of  New  Jersey.  Like  the  stable-fly,  it 
is  a  blood-sucker,  and  both  species  are  often 
found  on  animals  at  the  same  time,  keeping 
them  in  that  state  of  constant  irritation 
which  prevents  their  proper  feeding  and 
digesting,  and  keeps  them  poor  and  in  no 
condition  to  produce  a  free  flow  of  milk. 
Not  only  in  the  fields  or  pastures  are  the 
cattle  annoyed  by  these  insects,  but  in  the 
stable  as  well,  so  that  the  animals  get  no 
rest  night  or  day.  Eggs  are  laid  in  fresh 
cow-dung,  and  before  this  has  an  oppor- 
tunity to  dry  under  ordinary  conditions,  the 
larvae  are  full-grown  and  ready  to  pupate.  It  is  the  immense 
number  of  these  insects  that  makes  them  dreadful,  and  when  the 


Egg    of    horn-fly.  —  i, 
unhatched,     from    side; 

2,  hatched,   from   front; 

3,  same,  from  side,  to 
show  lid-like  structure; 
all  enlarged. 


360 


AN   ECONOMIC  ENTOMOLOGY. 


Fig.  418. 


species  first  made  its  appearance  in  the  Eastern  United  States, 
horrible  tales  were  told  of  the  destruction  caused  among  herds 
of  cattle.  As  a  matter  of  fact,  except  for  the  irritation,  it  causes 
no  injury.  Much  can  be  done  to  prevent  the  increase  of  this 
insect  by  destroying  the  breeding-places.  In  the  stable,  the  stalls 
and  their  surroundings  should  be  kept  absolutely  clean,  and 
whitewash  should  be  liberally  applied.  The  manure  should  be 
mixed  at  once  with  either  kainit  or  land  plaster,  which  absorbs 

the  moisture  and  makes  the  mass 
unfit  for  the  larva,  while  at  the  same 
time  it  does  not  injure  its  value  as  a 
fertilizer.  A  boy  should  be  sent 
through  the  pasture  every  two  or 
three  days  with  a  shovel,  and  di- 
rected to  spread  out  every  dropping 
in  such  a  way  as  to  cause  it  to  dry 
up  or  wash  away  readily  before  the 
larvae  can  complete  their  develop- 
ment. The  flies  can  be  kept  from 
the  animals  by  the  use  of  fish  oil 
and  crude  carbolic  acid,  applied  to 
those  parts  not  readily  reached  by 
the  tail.  The  proportions  of  fish 
oil  and  carbolic  acid  are  not  im- 
portant ;  enough  of  the  crude  acid 
to  give  a  decided  odor  is  all  that  is  necessary,  and  one  appUcation 
will  usually  suffice  to  protect  an  animal  for  five  or  six  days. 

Another  series  of  decidedly  troublesome  flies  we  find  in  the 
Anthomyiids,  whose  larvae  are  frequently  root-infesting  maggots. 
The  adults  closely  resemble  the  common  house-flies,  but  are  usu- 
ally somewhat  smaller  in  size  and  slighter  in  build.  They  are 
found  in  fields  on  the  ground,  on  vegetation  of  all  kinds,  and 
also  commonly  enough  in  our  houses  on  the  windows,  where  they 
are  usually  mistaken  for  the  true  house-fly.  Recognition  of  the 
species  of  these  flies  is  a  matter  of  no  great  importance  practi- 
cally ;  but  it  may  be  assumed,  where  flies  resembling  the  ordinary 
household  pest  in  all  save  size  are  noticed  in  any  number  about 
crops  subject  to  infestation  by  root-maggots,  that  we  have  mem- 
bers of  this  Anthomyiid  series  to  deal  with.     They  are  often  very 


Larva  of  horn-fly,  i  ; 
structural  details,  3,4, 


THE    INSECT   ]VORLD. 


361 


Cabbage-maggot,  Phorbia  brassica. — a,  larva  ;    b,  pupa  ; 
c,  adult ;  d,  its  head  ;  e,  antenna. 


injurious  to  cabbage  and  cauliflower,  as  well  as  to  onions,  rad- 
ishes, turnips,  beets,  and  other  root  crops,  while  other  species 
attack  planted  seeds 

like  those  of  melons  ^^^-  4'9- 

and  even  corn.  Oc- 
casionally, instead  of 
attacking  roots,  the 
maggots  are  found 
boring  in  thick  or 
fleshy  leaves,  and 
then  they  make 
mines  or  galleries  be- 
tween the  upper  and 
lower  surfaces,  often 
doing  much  injury. 
Sometimes  their  hab- 
its are  more  hke 
those  of  the  house- 
fly, and  the  larvae  are 
scavengers,  while  a 
few  have  been  recorded  as  parasites  on  other  insects.  The 
group,  therefore,  is  one  with  diverse  habits,  but  usually  to  be 
looked  upon  with  considerable  suspicion.  Perhaps  the  best 
known  of  the  root-maggots  is  the  larva  of  Phorbia  brassicce,  in- 
festing cabbage,  cauliflower,  and  other  plants  of  the  same  natural 
family.  Eggs  are  laid  on  the  ground  soon  after  the  plants  are 
set  out  in  the  fields.  The  larvce  make  their  w^ay  into  them  as 
soon  as  they  are  hatched,  gnawing  or  rather  scraping  the  tissue, 
so  as  to  enable  them  to  absorb  the  plant  juices,  for  they  have  no 
jaws  for  mastication.  Decay  sets  in  where  the  insects  work,  and 
this  favors  their  feeding,  so  in  a  few  days  they  destroy  the  tissue 
of  the  plant  and  stem  a  little  below  the  surface  so  completely  that 
it  dies.  Later  crops  are  not  so  much  harmed,  as  a  rule,  and  if 
plants  can  be  preserved  until  they  reach  a  good  size,  they  fre- 
quently sustain  considerable  maggot  attack  without  serious  in- 
jury. As  to  the  best  remedies  against  this  particular  insect  we 
are  yet  somewhat  uncertain.  Putting  a  pad  or  disk  of  tarred 
paper  on  the  stems  of  the  plants  when  they  are  set  out  has  been 
found  successful  in  preventing  the  adult  from  laying  eggs,  or  the 


362  AN  ECONOMIC  ENTOMOLOGY, 

larvae  from  getting  at  the  desired  point,  smce  they  seem  to  be 
unable  to  live  exposed  to  sunlight.  Ground  tobacco,  kerosene 
and  sand,  plaster,  soot,  ashes,  and  other  materials  placed  at  the 
base  of  the  plants  act  like  the  tarred  paper  as  a  mechanical  pro- 
tection, and  must  be  applied  before  the  eggs  are  laid,  else  they 
will  prove  ineffective.  Bisulphide  of  carbon  injected  below  the 
root  system  has  been  used  with  a  considerable  degree  of  success, 
the  fumes  filtering  through  the  soil  and  killing  the  insects  at 
work  on  the  plant  without  injuring  the  plant  itself  An  injector 
devised  for  the  especial  purpose  has  been  made  by  Mr.  J.  J, 
McGowen,  of  Ithaca,  New  York,  and  perhaps  the  appHcation  of 
this  substance  is  the  most  certain  and  satisfactory  remedy  that 
has  been  proposed.  It  should  be  used  when  the  soil  is  moist, 
but  not  water-soaked.  There  are  two  or  three  broods  in  the 
course  of  the  year,  according  to  latitude.  The  winter  is  passed 
either  as  a  pupa  below  the  surface  or  as  an  adult  in  barns, 
houses,  etc.,  and  the  species  is  tided  over  between  cultivated 
crops  by  the  cruciferous  weeds.  Hence  clean  culture  and  the 
prompt  removal  of  all  crop  remnants  are  urgently  indicated. 
Carbolic  acid  and  kerosene,  emulsified  with  soap  according  to  the 
formulas  elsewhere  given,  have  proved  effective  as  killing  agents 
when  the  maggots  have  begun  feeding.  Pour  about  half  a  pint 
around  the  base  of  the  infested  plant,  diluting  the  carbolic  acid 
emulsion  thirty  times  and  the  kerosene  emulsion  twelve  times. 

Radishes  frequently  suffer  from  the  attacks  of  the  same 
maggots,  and  they  are  more  difficult  to  deal  with  here,  because 
they  puncture  the  fleshy  root  and  make  channels  through  it  in 
every  direction,  safely  beyond  the  reach  of  any  insecticide  appli- 
cation. It  rarely  pays  to  put  expensive  substances  on  radishes, 
because  the  margin  of  profit  is  too  small  ;  but  considerable 
benefit  may  be  derived  from  proper  methods  of  fertilizing,  and 
the  mixture  that  seems  to  offer  the  best  chance  for  success  is 

Nitrate  of  soda 700  pounds. 

Ground  rock 1000  pounds. 

Muriate  of  potash 300  pounds. 

Apply  soon  after  the  plants  are  up,  or  when  the  leaves  are  about 
an  inch  long,  at  the  rate  of  five  hundred  pounds  per  acre,  and 
before  or  during  a  rain.     The  application  made  at  this  time  seems 


THE    INSECT   WORLD. 


l^l 


to  reach  the  iiia_oL>ots  just  when  tlu-y  are  hatchuior,  and  becomes 
effecti\'e  for  that  reason.  AppHcd  later,  when  the  insects  have 
already  made  tlieir  way  into  the  radishes,  it  would  be  useless. 
Here  tiie  farmer  must  necessarily  make  a  few  observations  of  his 
own  to  determine  the  proper  time  for  applying  the  fertilizer 
remedy,  and  this  is  not  difficult.  The  flies  lay  the  eggs  in  little 
masses  on  the  surfice  of  the  ground  near  to  the  infested  plants. 
They  are  white,  slender,  and  cylindrical,  nearly  one-sixteenth  of 
an  inch  in  length,  and  quite  visible  on  close  examination.  When 
these  eggs  are  found  generally  distributed  over  the  fields  the 
time  to  make  the  insecticide  application  has  arrived,  because  they 
hatch  only  a  few  days  after  they  are  laid,  and  the  young  larvae 
must  be  reached  then  or  not  at  all.  The  carbolic  acid  emulsion 
diluted  thirty-five  times  may  also  be  applied  with  good  prospects 
of  success  in  killing  the  maggots,  or  the  ground  tobacco  may  be 
used  over  the  rows  just  as  soon  as  the  plants  are  up. 

The  onion-maggot,  Phorbia  ceparian,  is,  perhaps,  next  in  im- 
portance, and  its  habits  are  essentially  the  same  as  those  given 
for  the  cabbage-maggot, — that  is,  the  eggs  are  laid  by  the  fly 
quite  early   in    spring, 

next  the  onion  stems  or  ^'^-  42o- 

leaves  at  the  surface  of 
the  ground,  and  prefer- 
ably in  young  onion 
beds.  In  the  latitude  of 
New  Jersey  this  occurs 
in  May,  but  the  date  va- 
ries somewhat  accord- 
ing to  the  season  and  to 
the  time  at  which  these 
plants  are  started.  The 
larvee  w^ork  their  way 
into  the  bulb  at  once 
and  begin  their  scraping 
and  gnawing,  leading  to 

the  rapid  decay  and  death  of  the  plant.  Matters  are  even  more 
serious  here  than  in  the  cabbage,  because  where  a  bulb  has  been 
started  in  decay,  it  usually  continues,  even  if  the  maggots  are  de- 
stroyed, and  in  the  case  of  scullions,  they  become  unmarketable. 


The  onion-maggot. — Larva,  pupa,  adult,  and  section 
of  an  infested  onion. 


364  A^   ECONOMIC  ENTOMOLOGY. 

The  maggots  attain  their  growth  about  the  end  of  May  or  early 
in  June,  and  before  the  middle  of  that  month  a  second  brood  of 
flies  may  be  found  in  the  fields.  This  second  brood  is  often 
much  the  most  injurious,  and  quite  frequently  it  attacks  seedling 
onions,  ruining  entire  beds.  The  older  plants,  if  they  have 
reached  this  date  unharmed,  are  usually  safe  for  the  year.  Exactly 
how  many  broods  there  are  has  not  been  accurately  ascertained, 
and  probably  the  number  varies  somewhat  according  to  latitude. 
We  do  know  that  the  insects  pass  the  winter  partly  in  the  pupa 
stage  in  the  ground,  and  partly  as  adults  in  barns,  farm-houses, 
and  other  sheltered  localities.  Many  measures  to  prevent  injury 
have  been  proposed,  none  with  any  marked  success,  except  those 
here  mentioned.  The  most  promising  is  sand  soaked  in  kerosene, 
one  cupful  to  a  pail  of  dry  sand,  and  placed  at  the  base  of  the 
onion  plants  along  the  rows.  This  prevents  egg-laying  by  the 
fly,  kills  any  young  larvae  that  may  attempt  to  work  through  it, 
and  seems  to  have  been  quite  satisfactory  where  tested  ;  but  it  is 
obviously  not  a  suitable  measure  for  application  on  a  large  scale. 
In  New  Jersey  tons  of  onion  seed  and  sets  are  raised  annually, 
and  the  following  practice  has  been  found  uniformly  successful. 
Keep  a  close  watch  for  the  first  signs  of  maggots  ;  carefully  lift 
out  and  destroy  all  infested  plants  that  have  wilted  down  so  far 
that  they  cannot  survive,  and  so  kill  the  more  advanced  maggots. 
Turn  away  the  earth  from  the  rows  with  a  hand-plough  so  as  to 
expose  the  root  system  in  part,  then  apply  broadcast  about  six 
hundred  pounds  of  kainit  and  two  hundred  pounds  of  nitrate  of 
soda  per  acre  ;  turn  back  the  earth  to  the  plants,  and  this  will  put 
a  period  to  the  injury.  The  application  is  best  made  just  before 
or  during  a  rain,  or  immediately  after  a  shower  that  has  wet 
down  pretty  thoroughly.  The  object  is  to  get  the  salty  fertilizers 
dissolved  rapidly  and  brought  into  direct  contact  with  the  roots 
of  the  plant,  and,  of  course,  with  the  insects  as  well.  This 
method  has  proved  entirely  satisfactory  in  New  Jersey,  and  on 
light  lands  it  will  probably  act  equally  well  in  other  localities  ; 
but  it  has  never  been  tested  on  heavy  land,  and  the  action  may 
not  be  entirely  the  same.  The  application  of  the  fertilizer  has  the 
advantage  of  imparting  additional  vigor  to  the  plant,  and  stimu- 
lates it  to  overcome  such  injury  as  may  have  been  already  caused. 
It  is  a  good  plan  always  and  under  any  circumstances  to  care- 


THE    IXSECT   WORLD.  365 

fully  take  out  and  destroy  plants  that  have  wilted  down  beyond 
recovery,  because  in  this  way  the  maggots  are  destroyed  or  pre- 
vented from  coming  to  maturity. 

Other  root-maggots  may  be  treated  on  the  lines  just  laid  down, 
and  nothing  can  be  gained  by  multiplying  instances.  Too  little 
is  known  of  most  of  the  leaf-miners  to  give  any  general  directions 
concerning  the  methods  which  may  be  used  to  check  them  ;  but 
one  remedy,  or  rather  preventive  measure,  is  always  useful.  A 
crop  of  infested  leaves  should  always  be  disposed  of  as  soon  as 
possible.  For  instance,  if  beet  leaves  are  attacked  at  the  time 
the  roots  are  harvested,  they  should  be  at  once  destroyed,  and 
with  them  the  insects  yet  in  the  plants.  In  this  way  much  can 
be  done  to  lessen  their  number  for  the  ensuing  season.  Direct 
applications  for  leaf-miners  are  unsatisfactory,  because  of  the 
difficulty  of  reaching  them. 

The  remainder  of  the  Muscid  flies  differ  from  all  the  preceding 
in  that  they  have  no  perceptible  winglct  or  alulct  just  below  the 
anterior  wings.  If  the  "  blow-fly"  or  the  "  house-fly"  be  exam- 
ined, it  will  be  found  that  just  behind  the  base  of  the  large  wings 
there  is  a  little  flap  resembling  in  appearance  a  minute  wing. 
This  is  called  the  "  winglet"  or  "alulet,"  and  it  is  more  or  less 
obvious  in  all  the  Muscids  of  which  we  have  heretofore  spoken. 
It  is  absent  in  all  the  other  groups,  and  serves  to  divide  this 
large  family  into  two  fairly  distinct  series. 

We  find  it  absent  in  a  large  series  of  flies  belonging  to  the 
Trypetids  and  Ortalids,  which  are  usually  small  in  size,  often 
metallic  in  color,  and  with  the  wings  frequently  banded  or  mot- 
tled. Some  of  the  species  have  the  habit  of  strutting  up  and 
down  with  the  wings  elevated  and  spread  out,  and  this  has  given 
them  the  name  "peacock  flies."  They  are  gracefully  built  in 
most  instances,  and  are  noticeable  by  keeping  the  wings  in  con- 
stant motion  even  when  feeding  or  walking  about  on  flowers, 
where  they  are  most  frequently  found.  They  fly  rather  slowly, 
and,  as  a  rule,  are  easily  captured.  The  abdomen  of  the  female 
frequently  ends  in  an  extensile,  horny-tipped  ovipositor,  by 
means  of  which  the  eggs  are  laid  in  the  plant  tissue  in  which  the 
larvae  feed.  Most  of  the  members  of  the  series  feed  in  plant 
tissue  of  some  kind,  either  in  leaves,  in  stems,  or  in  fruits,  and  a 
number  of  them  are  gall-makers.     The  most  notable  instance  of 


366 


AN   ECONOMIC   ENTOMOLOGY. 


the  latter  type  in  the  Eastern  United  States  is  seen  in  the  round 
swelUngs  so  frequently  found  on  the  stems  of  golden-rod.  A 
number  of  species  are  locally  injurious  to  fruits,  but  there  seems 
to  be  no  one  injurious  form  generally  distributed  throughout  this 
country.  In  the  Northern  and  Eastern  United  States  the  so- 
called  "  apple" -maggot,  Trypcta  pomonella,  is  the  only  one 
causing  trouble,  the  fly  laying  its  eggs  in  the  tissue  of  the  apple  by 

Fig.  421. 


Trypeta  pomonclla,  parent  of  the  apple-maggot. 


piercing  the  skin  with  its  horny  ovipositor.  The  little  maggots 
channel  the  fruit  in  every  direction,  causing  it  to  rot  or  become 
unsalable.  When  full-grown  they  pupate  below  the  surface  of 
the  ground,  or  even  among  rubbish  on  the  surface,  or  in  crevices. 
Indeed,  they  are  not  at  all  particular,  and  transform  wherever 
they  can  find  an  opportunity  to  do  so,  including  the  barrels, 
boxes,  or  bins  in  which  infested  apples  have  been  kept.  None  of 
these  fruit  flies  can  be  reached  by  insecticides,  nor  is  there  any 
fair  chance  of  reaching  the  adults,  and  the  only  method  that 
is  effectual  is  the  prompt  removal  and  destruction  of  infested 


THE    INSECT    WORLD. 


367 


fruit.  Windfalls  should  be  picked  up  constantly  and  destroyed 
at  once.  Summer  varieties,  especially  sweet  types,  are  most  in- 
fested, and  these  should  be  sent  to  market  at  once  if  the  apples 
are  marketable,  or  if  they  are  not,  they  should  be  disposed  of  in 
some  eifective  manner  to  prevent  the  maturing  of  the  flies.  They 
seem  to  be  more  common  in  the  Northeastern  States,  extending 
southward  only  to  Central  New  Jersey.  South  of  this  point  they 
seem  to  be  unknown,  or  so  rare  as  not  to  be  injurious. 

Probably  every  one  has  noticed  in  the  fall,  at  cider  making,  or 
when  grapes  are  pressed  for  wine,  or,  in  fact,  whenever  there  is 
an  accumulation  of  fruit  of  any  kind  in  which  fermentation  or 
decay  has  started  in  ever  so  slight  a  degree,  that  swarms  of  little, 
yellowish  flies  make  their  appearance,  easily  distinguished  by 
the  bright  coral-red  color  of  the  eyes.  No  specimens  may  have 
been  noticed  previously  ;  but  just  as  soon  as  the  material  at- 
tracting them  makes  its  appearance,  swarms  are  seen  coming 
from  no  one  knows  where.  They  lay  their  eggs  in  the  ferment- 
ing or  decaying  mass, 
and  a  few  hours  after- 
wards there  will  be  an 
abundance  of  small, 
white,  wriggling  mag- 
gots. These  become 
mature  in  three  or  four 
days,  and  after  another 
day  or  two  in  the  pupa 
state,  they  develop  into 
adult  "pomace  flies," 
species  of  Drosophila.  The  insects  are  sometimes  annoying 
and  a  little  troublesome,  but  scarcely  injurious,  and  it  is  only 
because  they  are  so  common  and  occur  so  suddenly  in  large 
numbers  that  they  are  mentioned  here.  Little  attention  is  paid 
to  the  larvae  either  in  wine  or  cider  making,  because  they  are 
thrown  out  in  the  process  of  fermentation,  and  do  not  in  any  way 
affect  the  quality  of  the  resulting  product. 

To  this  same  family  belong  the  "  skippers"  M^hich  are  found  in 
cheese  and  sometimes  in  other  kinds  of  provisions.  The  term 
is  derived  from  the  habits  of  the  larvte,  which  move  about  by  a 
series  of  little  jumps  somewhat  resembling  those  of  the  larvae 


A  pomace  fly  and   its  larva,  Drosophila  species; 
enlarged. 


y 


368 


ajV  economic  entomology. 


Piophila  casci,  parent  of  ' 
etc. 


'  skippers"  in   cheese, 


of  the  Cecidomyida:.  They  produce  a  Uttle  black  fly,  Piophila 
casei,  similar  to  the  house-fly  in  appearance,  but  much  smaller, 
and  the  only  way  to  protect  provisions  is  to  keep  them  con- 
stantly covered.  They  sometimes  become  an  intolerable  nuisance 
in  smoke-houses,  attacking  ham,  bacon,  and  the  like  during  the 

process  of  smoking,  or  be- 
FiG.  423.  fore  they  can  be  cased,  and 

the  value  of  the  provision 
is  frequently  impaired  by 
the  development  of  these 
maggots.  Where  a  house 
is  once  thoroughly  in- 
fested, the  flies  are  found 
in  swarms  everywhere, 
ready  to  attack  the  meats 
as  soon  as  there  is  the 
least  opportunity.  Under 
such  circumstances  thor- 
ough measures  are  neces- 
sary to  get  rid  of  them.  In  the  first  place,  windows  should  be 
closely  screened  to  prevent  their  entry  from  outside  ;  the  walls 
should  be  whitewashed  frequently,  so  as  to  keep  all  crevices 
filled  up  ;  the  floors  should  be  kept  clean,  and  should  be  as  solid 
and  smooth  as  possible,  to  prevent  the  development  of  maggots 
in  crevices  filled  with  greasy  substances.  The  flies  can  be  killed 
by  fumigating  with  tobacco  or  pyrethrum,  and  this  should  be 
done  by  closing  up  the  rooms  tightly  in  the  evening  after  work 
is  done,  or  on  a  Sunday  or  other  day  when  work  ceases,  and  a 
sufficient  quantity  of  either  tobacco  or  pyrethrum  should  be 
burnt  on  live  coals  to  comj)letely  fill  all  parts  of  the  rooms.  They 
should  be  left  tightly  closed  anywhere  from  eight  to  twenty-four 
hours,  and  at  the  end  of  this  time  the  flies  will  have  been  de- 
stroyed, but  the  maggots  will  not,  and  it  will  be  necessary  to 
repeat  this  operation  two  or  three  times,  at  intervals  of  (at  most) 
a  week,  to  destroy  the  flies  as  fast  as  they  hatch,  and  before 
they  have  an  opportunity  to  lay  their  eggs.  In  some  cases  bi- 
sulphide of  carbon  may  be  used  to  fumigate  ;  but  this  must  be 
done  when  there  is  no  fire  on  the  premises,  and  the  house 
should  be  left  closed   twelve  hours  at  least,   and   should  then 


THE    lA'SECT   WORLD. 


369 


A  louse-fly,  Olfersia  species. 


be  aired   until  no  trace  of  odor  remains  before  fires  are  again 
introduced. 

The  last  family  in  the  Diptcra  to  which  we  need  call  attention 
are  the  "  lousc-fiics,"  or  Hippoboscidcc,  frequently  separated  as 
a  sub-order  under  the  term  Piipipara,  the  latter  being  applied 
because  of  the  curious  method  of  reproduction.  The  flies  are 
parasites,  living  largely  upon  birds,  but  sometimes  upon  animals, 
and   the  eg^   not   only 

develops      within      the  Fig.  424. 

body  of  the  female,  but 
the  larva  becomes  nearly 
full-grown  in  the  same 
position,  and  practically 
attains  the  pupa  state 
before  it  is  extruded. 
In  these  species  the  ab- 
domen is  somewhat  flat- 
tened and  oval  in  form, 
of  a  thick,  leathery  con- 
sistency,   with    a    very 

large  anal  opening,  and  from  the  circumstances  of  the  case  only 
one  larva  at  a  time  is  produced,  so  that  the  flies  produce  young 
only  at  considerable  intervals.  The  whole  body  is  depressed  or 
flattened,  and  birds  of  prey  are  most  usually  affected.  It  is  rare 
to  find  a  hawk,  eagle,  or  owl  upon  which  several  specimens  of 
these  peculiar  flies  cannot  be  found.  They 
move  about  rapidly,  and  their  first  impulse  is 
always  to  seek  shelter  when  driven  from  their 
original  host.  Thus,  in  handling  hawks  that 
have  just  been  shot,  the  flies  frequently  dart 
upon  the  hunter  and  make  their  way  under  his 
clothing  and  to  his  body. 

A  few  species  are  wingless,  and  among  them 
is  the  so-called  "sheep-tick,"  Melophagus 
ovimis,  which  is  usually  looked  upon  as  a 
louse,  and  resembles  one  in  the  prominent 
proboscis,  the  lack  of  wings,  and  the  strongly  developed  legs, 
on  which  the  claws  are  very  prominent.  This  "sheep-tick"  is 
the  only  troublesome  species,  and  it  can  best  be  kept  in  check 

24 


Fig.  425. 


Sheep-ticK,    Melopha- 
gus ovinus. 


37° 


AN  ECONOMIC  ENTOMOLOGY. 


by  frequent  dipping,  using  a  carbolated  dip  which  readily  de- 
stroys the  insect.  Thorough  washing  after  shearing  will  usually 
clear  the  animals  completely,  and  if  the  entire  herd  be  once 
freed,  it  will  remain  so  until  infested  animals  are  introduced. 
The  parasites  are  able  to  move  from  one  to  the  other  only  when 
the  animals  are  herded  close  together. 

Yet  more  louse-like  in  appearance  is  the  little  whitish  creature, 
Braula  c<zca,  found  upon  the  honey-bee  as  a  parasite  ;  but  it 

Fig.  426. 


Bee-louse,  Braula  ccrca,  and  its  larva  ;  much  enlarged. 

seems  to  be  rather  rare,  and,  in  our  country  at  least,  does  not 
assume  the  dimensions  of  a  serious  pest. 


CHAPTER    IX. 


THE    HYMENOPTERA. 


Bees,    Wasps,  A)its,  Smv-flies,  etc. 

There  is  no  order  of  greater  interest  than  this,  containing  as 
it  does  the  bees,  wasps,  and  ants,  the  most  useful  as  well  as  the 
most  intelligent  of  the  insects.  By  treating  them  last,  the  inten- 
tion is  not  to  suggest  that  they  are  lowest,  but  rather  that  they 
are  the  culminating  point  in  the  development  of  the  class.  Here 
we  find  social  organizations  not  unlike  some  of  our  own  systems 
of  government,  but   more   complete   and  running   much    more 


THE    INSECT   WORLD. 


371 


smoothly.  We  find  division  of  labor  carried  to  an  extreme  ; 
combination  for  special  purposes  ;  skill  and  energy  in  the  prepa- 
ration of  homes  ;  and,  finally,  we  discover  the  helpless  young 
cared  for  by  parents  or  nurses.  It  is  only  in  the  Hymc7ioptera 
among  insects  that  we  find  true  babies, — that  is,  young  that  must 
be  fed  and  tended  until  they  are  ready  to  assume  the  adult  form. 
Nowhere  else  do  we  find  larva?  fed  on  anything  but  simple, 
natural  food  ;  but  by  many  bees  a  mixture  is  prepared  and  fed  ; 
not  honey  or  pollen  alone,  but  a  combination  of  the  two  in  defi- 
nite proportions  is  given,  and  these  proportions  vary  with  the 
sex  of  the  larxa. 

Members  of  the  order  Hymenoptera  may  always  be  distinguished 
by  the  presence  of  four  transparent  wings,  the  anterior  always  the 
larger,  the  secondaries  frequently  very  small.  They  are  not  cov- 
ered with  scales,  but  are  often  set  with  small  hair,  and  the  cells 
and  veins  are  comparatively  few  in  number  ;  never  netted  as  in  the 
Neuroptej'a.  The  mouth  parts  are  mandibulate,  or  formed  for 
biting,  but  in  many  of  the  families  there  is  also  developed  a  large 
tongue-like  structure  which  serves  for  lapping,  none  of  the  Hy- 
menoptera being  strictly  haustellate,  or  sucking  insects.  The 
metamorphosis  is  complete. 

Taken  as  a  whole,  the  order  contains  beneficial  insects  ;  but  as 
there  is  no  rule  without  exceptions,  so  we  find  here  also  one 
series  the  species  of  which  are  vegetable  feeders.  These  are  in- 
cluded in  the  families  Teiithredinidce  and  Urocendce,  the  "saw- 
flies"  and  "horn-tails." 

The  term  "saw-flies"  is  used  to  indicate  a  series  of  species 
peculiar  by  the  structure  of  the  ovipositor,  which  is  made  up  of  a 
number  of  parallel  blades  toothed  at  the  edge,  by  means  of  which 
the  insects  are  enabled  to  cut  pockets  or  slits  in  leaves  or  other 
vegetable  tissues  to  receive  the  eggs.  They  are  further  peculiar 
by  having  the  abdomen  sessile,  or  joined  for  its  full  width  to  the 
base  of  the  thorax,  and  the  wings  are  rather  larger  in  proportion 
to  the  body  than  in  other  groups.  The  larvae  are  caterpillar-like 
in  appearance,  but  they  always  have  at  least  one  more  pair  of 
prolegs  than  any  caterpillar, — six  pairs  or  more,  of  which  one 
pair  is  anal, — which  renders  them  easily  distinguishable.  They 
are  often  more  or  less  slimy  in  appearance  and  to  the  touch,  and 
perhaps  a  majority  have  the   habit  of  coiling  the  posterior  por- 


372 


AN   ECONOMIC  ENTOMOLOGY. 


Fig.  428. 


tion  of  the  body  around  the  edge  of  the  leaf  or  twig  while  feed- 
ing. This  is  quite  a  characteristic  peculiarity,  and  there  is  rarely 
excuse  for  mistaking  the  larva  of  a  saw-fly  for  that  of  a  Lepidop- 
teron,  even  without  counting  the  prolegs.  Many  of  these  larva? 
are  injurious  to  cultivated  plants,  and  some  of  them  are  known  to 
farmers  as  ' '  slugs' '  or  "  worms  ;' '  for  instance,  we  have  the 
"currant- worm,"  the  "grape-slug,"  the  "rose-slug,"  and  the 
"pear-slug."  When  these  larvae  are  full-grown  they  form  thin, 
tough,  parchment-like  cocoons,  in  which  they  change  to  pupae, 
sometimes  on  the  plant  on  which  they  feed,  sometimes  a  little 
below  the  surface  of  the  ground. 

Perhaps  none  of  the  members  of  this  family  are  better  known 
than  the  "currant-worm,"  or  "slug,"  Nematus  ribesii,  which  is 
an  imported  insect,  and  annually  does  great  injury  where  its  food 
plant  is  raised  on  a  large  scale.  The  flies,  which  are  easily  dis- 
tinguishable by  a  rather  deep  yellow  body,  may  be  seen  sitting 
upon  the  foliage,  or  flying  about  heavily  as 
soon  as  the  leaves  of  the  currants  are  toler- 
ably well  developed  in  spring,  and  we  may, 
even  at  that  time,  find  on  the  under  sides, 
arranged  along  the  veins,  series  of  little 
white  eggs  laid  by  them.  The  larvae  soon 
make  their  appearance  and  feed  ravenously, 
frequently  stripping  a  bush  completely  in 
the  course  of  a  few  days.  I  have  seen  rows 
of  currants  covering  an  acre  or  more  almost 
entirely  devoid  of  leaves  and  the  fruit  hang- 
ing to  bare  twigs.  There  are  two  or  three 
broods  in  the  course  of  a  season,  depending 
upon  latitude,  the  latter  rarely  as  abundant 
as  the  first  and  second,  and  practically  not 
nearly  so  destructive.  The  larva  is  green, 
dotted  with  black,  and  nearly  an  inch  in 
length. 

On  pears  we  frequently  note  a  very  dark  green  slug,  the  larva 
of  Eriocampa  cerasi,  which  is  more  or  less  slimy  to  the  touch. 
On  young  trees  this  sometimes  does  much  injury  by  scraping 
the  upper  side  of  the  foliage  until  it  dries  and  withers,  falling  to 
the  ground  in  midsummer. 


Pear-slug,  larva  of  Erio 
canipa  cerasi. 


Fig.  427. 


Fig.  431. 


Fig.  427.  currant-worm.— a,  a,  male  and  female  adult  ;  b,  larvae;  c,  pupa  -n  (d)  cocoon; 
e,  eggs.  Fig.  431,  Phyllu-cus  JiavivetUris.—a,  female  adult ;  b,  c,  male  and  female  abdomen  ; 
d,  spur  of  anterior  tibia. 

373 


374  A^  ECONOMIC  ENTOMOLOGY. 

On  grapes  there  are  often   black-dotted  slugs,  the  larvse  of 
Blennocampa  pygmcBa,  that  do  some  injury  ;  and  on  roses  almost 
every  grower  has  been  annoyed  by  numer- 
■  ous  green   slugs,  the  larvae  of  Monostegia 

ros(£,  which  make  their  appearance  early  in 
the  season. 

Raspberries  are  sometimes  severely  in- 
jured by  little  spiny  slugs,  the  larvae  of 
Monophadtius  rubi,  that  appear  in  June  or 
early  July,  first  eating  round  holes  in  the 
leaves,  but  eventually,  when  they  become 
Grape-slug,  larva  of  y?/<'«-    numerous  cuough,  taking  the  foliage  com- 

nocampa  pygmcra.  ^  °.  ^ 

pletely.  Many  other  cultivated  plants,  in- 
cluding the  strawberry,  are  attacked  by  these  saw-fly  larvae  ;  but 
their  habits  are  very  similar,  and  the  remedies  to  be  adopted 
against  them  are  also  very  much  the  same. 

The  largest  of  our  American  species,  Cimbex  aviericana,  is 
found  on  willow,  sometimes  in  considerable  number,  as  a  pow- 
dery, whitish  larva  an  inch  and  a  half  in  length,  with  a  broad 
dark  stripe  on  its  back. 

Experience  has  shown  that  all  these  species  are  very  suscep- 
tible to  the  influence  of  white  hellebore,  and  that  even  a  small 
quantity  is  quickly  fatal.  Infested  plants  can,  therefore,  be 
cleared  in  a  few  hours  by  a  thorough  drenching  with  a  decoction 
of  white  hellebore,  used  at  the  rate  of  one  ounce  in  one  gallon  of 
water  ;  or  the  plants  may  be  dusted  with  the  powder,  undiluted 
or  mixed  with  several  times  its  own  bulk  of  cheap  flour.  Any 
stomach  poison — e.g. ,  the  arsenites  or  tobacco — ^will  answer  as 
well  as  hellebore,  while  on  the  slimy  types  even  fine  road-dust 
will  quickly  choke  them  to  death.  Air-slaked  or  dry  hydrate  of 
lime  burns  through  them  in  less  than  an  hour  when  carefully  ap- 
plied. These  insects  are  so  easily  killed  that  it  is  the  fault  of  the 
farmer  himself  if  he  suffers  injury. 

The  "horn-tails"  resemble  the  "saw-flies"  in  a  way,  but  the 
character  of  the  ovipositor  is  different  and  rather  more  like  an 
auger  or  borer  than  hke  a  saw.  So,  too,  the  species  are,  as  a 
rule,  internal  feeders  instead  of  eating  openly  upon  the  foliage. 
The  larvae  are  usually  slender,  white  or  nearly  so,  and  in- 
fest plants  ranging  from  the  stems  of  wheat  to  the  trunks  of 


THE    INSECT    WORLD. 


375 


trees. ,  Some  forms  live  in  blackberry  and  raspberry  canes, 
others  in  grasses  ;  I  have  taken  a  species  from  alder,  and  in 
fact  a  very  large  number  of  plants  are  infested  by  these  boring 
Hymenoptcra.  The  largest  of  our  species  is  the  ' '  pigeon  Tre- 
mex,"   T.  columba,  the  larva  of  which  attacks  quite  a  consider- 

FiG.  430. 


Pigeon  Tretnex,    T.  columba. — a,  larva,  with  young  larva  of  Thalessa  fastened  to  its 
side  ;  b,  its  head  ;  c,  d,  female  and  male  pupae ;  e,  female. 


able  variety  of  trees,  including  maple,  elm,  hickory,  and  beech, 
and  bores  into  the  solid  wood,  usually  when  the  tree  is  beginning 
to  die,  or  is  even  dead,  but  not  decayed. 

Dealing  with  these  insects  is  always  rather  a  difficult  matter, 
because  we  have  no  means  of  getting  into  the  infested  plants  with 
insecticides.  We  are  again  reduced  to  farm  practice,  and  must 
arrange  our  methods  of  cultivation  in  such  a  way  as  to  reach  and 
destroy  the  insects  by  depriving  them  of  food.  Thus,  with  the 
Phylloecus  infesting  blackberry,  if  the  canes  are  topped  about 
midsummer,  or  a  little  before,  the  larvae   never  mature,  because 


376 


AN  ECONOMIC  ENTOMOLOGY. 


Fig.  432. 


the  wood  dries,  becomes  unsuitable  for  food,  and,  as  the  insect  is 
incapable  of  travelling,  it  starves  to  death. 

In  the  case  of  Cephus  pygmcsiis,  the  insects  boring  in  wheat, 
they  spend  the  winter  either  low  down  in  the  infested  stalk — i.e., 

in  the  stubble — or  in  the  soil  just 
below  the  surface,  in  either  the 
larval  or  pupal  condition.  The 
proper  remedy  is  to  burn  the 
stubble  as  soon  after  harvest  as 
possible,  or  to  plough  it  under 
deeply.  This  destroys  the  in- 
sects and  results  in  preventing 
injury  the  year  following.  We 
have  no  means  of  reaching  the 
larva  while  it  is  actually  working 
in  the  stem  of  the  plant.  The 
remedy  is  radical,  and  were  it 
universally  resorted  to,  would 
need  to  be  applied  only  at  inter- 
vals of  several  years. 

The  "gall-flies,"  belonging  to 
the  family  Cyriipidcs,  are  curi- 
ous creatures.  They  resemble 
minute  wasps  in  form,  and  gen- 
erally have  a  very  short,  chunky 
body,  which  is  often  compressed 
and  joined  to  the  abdomen  by  a  very  slender  petiole  or  stalk, 
in  sharp  contrast  to  the  species  heretofore  written  of.  These 
gall-flies  are  mostly  true  parasites  on  plants.  They  derive  their 
common  name  from  the  fact  that  they  produce  swellings,  protu- 
berances, or  "galls"  of  great  variety  on  vegetable  tissues  ;  some- 
times on  leaves,  on  twigs,  on  trunks,  or  even  on  roots  ;  and 
perhaps,  of  all  others,  the  oak  is  the  favorite  of  the  insects  of 
this  family,  bearing  the  greatest  variety  of  galls  on  all  its  parts. 
I  say  these  insects  are  mostly  plant  parasites,  and  intend  to  ex- 
press by  this  that  they  do  not  actually  eat  the  infested  vegetable 
tissue.  The  irritation  caused  by  the  larva  induces  an  abnormal 
growth  in  the  part  of  the  plant  infested,  and  in  a  cell  in  this 
growth  it  has  its  home.     Here  the  insect  reaches  maturity  with- 


Cephus  pygmo'us,  wheat-stem  saw-fly. 
— a,  outline  of  larva,  natural  size  ;  b, 
larva  enlarged;  c,  larva  in  wheat  stalk, 
natural  size;  <?,  adult  female;  y^  female 
parasite,  enlarged. 


THE    nVSECT   WORLD. 


377 


out  devouring  any  part  of  its  vegetable  envelope,  changes  to  a 
pupa,  and  emerges  from  the  gall,  leaving  it  intact,   except  for 
the  hole  through  which  it  emerged.     It  seems,  therefore,  as  if 
certain  abnormal  plant  ex- 
udations   secreted    in    the  Fig.  433. 
gall   form  the  actual  food 
of  the   larva,   and   it   is   a 
curious  and  interesting  fact 
that  the  same  species  in- 
variably  produces    in    the 
same  place  the  same  kind 
of  gall.     In  other  words, 
the  appearance  of  the  gall 
is   an    unfailing   index   for 
the  special  student  to  the 

species  that  made  it.  Many  interesting  problems  are  connected 
with  the  study  of  these  gall-flies  ;  for  instance,  in  some  species 
both  sexes  are  present  early  in  the  season,  but  in  the  second  or 
midsummer  brood  females  alone  make  their  appearance.     The 

Fig.  434. 


An  oak  gall-fly. 


Gall  made  by  the  larva  of  Cynips  q.  spongifica.—a,  larva  in  its  cell  ;  b,  point 
of  exit  of  adult. 

progeny  of  this  female  form,  which  may  or  may  not  resemble 
the  spring  form,  in  turn  produces  males  as  well  as  females.  Of 
other  species  no  males  are  yet  known,  and,  so  far  as  we  have 


378 


AN  ECONOMIC  ENTOMOLOGY. 


any  evidence  at  present,  there  is  a  continuous  breeding  by  female 
individuals  only. 

There  are  only  a  very  few  injurious  species  among  these  gall- 
flies.    Occasionally  we  find  on  blackberry  stems  an    irregular, 

warty  swelling,  and  if 
Fi<^-  435-  this  be  cut  into,  it  will 

be  found  full  of  cells 
occupied  by  these  little 
Cynipid  larvae.  This 
kind  of  gall  is  known 
as  "  multicellular,"  be- 
cause inhabited  by  nu- 
m  e  r  o  u  s  specimens. 
Similar  galls  are  found 
on  the  roots  of  rose 
and  plants  of  the  same 
natural  family,  and  in 
a  few  other  cases  cul- 
tivated plants  become 
subject  to  gall  growths. 
As  a  matter  of  fact 
these  galls  are  scarcely 
injurious,  because  in 
most  cases  the  plant 
continues  growing  be- 
yond them,  or  even  if 
a  shoot  is  lost,  perma- 
nent injury  is  rarely 
done.  Certain  species 
of  oak-galls  produce  a 
black  stain,  and  these 
were  at  one  time  al- 
most universally  employed  in  making  an  ink  of  remarkable  per- 
manence. Even  yet  the  law  in  some  States  requires  for  certain 
records  an  ink  of  which  oak-galls  is  one  of  the  ingredients. 

It  is  a  small  step  from  parasitism  upon  vegetation  to  parasit- 
ism upon  animals,  and  hence  it  is  not  surprising  to  find  that  some 
species  of  this  family  are  parasitic  on  other  insects.  The  differ- 
ences between  these  forms  and  the  true  gall-makers  are  not  easily 


a,  Pithy 
7iebulosus , 
pupa. 


gall  on  blackberry,  made  by  Diaslrophus 
b,   section    to    show   cells;    c,   larva;    rf, 


THE    hXSECT   WORLD. 


379 


pointed  out,  since  the  insects  are  usually  small  in  size  ;  indeed,  it 
is  a  matter  of  little  importance  to  the  farmer,  because  in  any  case 
he  can  look  uj)on  these  gall-wasps  with  indifference,  and  without 
much  fear  of  possible  injury  to  himself. 

There  is  a  very  large  series  of  parasitic  Hymenoptera,  and  't 
contains  a  number  of  families,  nearly  all  the  species  of  which  are 
beneficial.      To  the   practised  eye  a  doubt   rarely  exists  as  to 
whether  an  insect  is  parasitic  or  not  ;  but 
that  the  student  may  be  able  to  decide 
this  matter  for  himself  if  he  chooses,    it 
may  be  pointed  out  that  the  trochanter, 
the  little  segment  between  the  coxa  and 
femur  of  the  leg,  is  rather  peculiarly  de- 
veloped here.     It  is  normally  composed 
of  one  joint  only  in  all  the  bees,  wasps,  and 
ants,  whatever  their  size  or   appearance, 
but  it  is  two-jointed  in  all  the  parasites.        «-  two-jointed  trochanter 

,  .        ,  ,  .,  of   parasitic    Hvmcnoplera ; 

1  his  character  can  be  easily  seen  on  large     t,  normal  structure, 
specimens  with  or  without  a  lens,  but  on 

minute  species  it  becomes  more  difficult ;  and,  after  all,  in  most 
cases  the  farmer  is  justified  in  assuming  that  most  of  the  minute 
wasp-like  creatures  that  he  notices  are  parasites  and  beneficial. 

One  feature  characteristic  of  a  great  number  of  species  is  an 
external  ovipositor,  or  egg-laying  tube,  and  this  may  vary  from 
a  scarcely  visible  projection  to  an  enormously  developed  hair- 
like appendage  five  to  six  or  even  more  inches  in  length. 

There  may  be  frequently  seen  on  the  trunks  of  various  trees  a 
quite  large  ichneumon,  a  Thalessa,  yellow  or  black  in  color  ac- 
cording to  the  species,  which  has  its  long,  bristle-like  ovipositor 
forced  deep  into  the  wood,  and  so  firmly  fixed,  occasionally,  that 
it  is  unable  to  withdraw  it,  and  perishes  miserably.  Wherever 
this  occurs  the  trees  will  be  found  infested  by  borers,  and  all  but 
universally  this  ichneumon  is  accused  of  being  the  parent  of  the 
larva  that  produces  the  injury.  The  circumstantial  evidence  is 
all  against  it  ;  but  we  really  have  here  a  beneficial  species  which 
is  after  the  wood-boring  larva  of  the  "pigeon  Tremex."  The 
insects  seem  able  to  recognize  an  infested  tree,  and  pierce  the 
trunk  until  the  ovipositor  reaches  one  of  the  burrows  of  the  wood- 
feeding  larva.     In  this  an  egg  is  laid,  and  the  larval  parasite, 


Fig.  437. 


Long-tailed  ichneumon,  Thalessa  lunator. — a,  larva;  b,  head  of  same;  c,  pupa;  d,  tip  of 
pupal  ovipositor;  e,  female  adult;  /,  tip  of  abdomen,  seen  from  the  side;  g,  male  adult  ; 
h,  tip  of  abdomen. 
380 


THE    INSECT   WORLD. 


381 


when  hatched,  crawls  along  the  burrow  until  it  comes  into  contact 
with  its  host.  It  then  punctures  the  skin  and  remains  fixed  to 
the  outside,  sucking  the  juices  and  gradually  killing  the  borer. 

Fig.  438. 


Pimpla  conquisitor. — a,  larva  ;    c,  pupa;   rf,  adult;   other  references   are  to  structural 

details. 

By  no  means  all  of  our  "  ichneumons,"  even  of  those  belong- 
ing to  the  family  Ichuumonidcs,  have  external  ovipositors  ;  yet 
there  is  a  distinctive  character  in  their  appearance  which  is  easily 
recognized  but  hard  to  de- 
scribe. The  species  belong-  ^''^-  439- 
ing  to  the  typical  genus  Ich- 
7ieumon  have  rather  long, 
slender  forms,  with  flattened 
abdomen  and  no  external 
ovipositor.  They  are  often 
gaudily  colored,  the  antennae 
are  frequently  banded  with 
yellow,  and  many  are  metallic 
blue  or  green.  The  species 
are  usually  parasites  on  cater- 
pillars. One  of  the  largest 
and  most  frequently  noted  species  is  that  which  infests  the  larvae 
of  the  common  "swallow-tail"  butterflies.  It  is  orange-yellow 
in  color,  with  smoky-black  wings,  the  body  nearly  an  inch  in 


Tragus  excsorius  on   a  chrysalis  of  Papilio, 
from  which  it  has  emerged. 


382 


AN  ECONOMIC  ENTOMOLOGY. 


length,  and  the  wings  expanding  fully  an  inch  and  a  quarter  or 
even  more.  This  makes  the  species  easily  recognizable,  and  it 
will  serve  very  fairly  as  a  type  of  this  particular  branch  of  the 
family.  Species  of  this  size  usually  lay  only  a  single  o.g'g  in  the 
host,  and  in  the  case  of  the  "  swallow-tail,"  the  caterpillar  retains 
strength  enough  to  change  to  a  chrysalis  ;  but  from  this  chrysalis 
there  emerges  through  an  ugly  hole  in  the  side  the  Tragus  exe- 
son'us,  which  has  just  been  described.  Frequently,  however,  in 
smaller  species,  a  considerable  number  of  parasitic  larvae  develop 
in  one  caterpillar. 

Of  quite  a  different  type,  as  compared  with  those  just  described, 
are  the  species  of  Ophion.  These  are  large  or  very  large 
creatures,  black  or  honey-yellow  in  color,  and  the  bodies  are 

transversely      flattened     and 
Fig.  440.  squarely  cut  off  at  the   pos- 

terior extremity.  They  are 
thus  blade-like  in  shape,  and 
the  ovipositor  rests  concealed 
in  a  groove  in  the  squarely 
cut  off  end  segment.  Though 
these  insects  are  not  stinging 
Hymenoptera,  strictly  speak- 
ing, yet  the  ovipositor  is  so 
short  and  sharp  that  the  in- 
sects make  use  of  it  as  a 
means  of  defence.  They 
should  be  carefully  handled, 
therefore  ;  though  the  sting, 
if  "  hot"  for  a  few  moments, 
seems  not  to  be  so  poisonous 
as  that  of  the  bees  and  wasps. 
In  the  family  BraconidcE 
the  species  are  smaller,  as  a 
rule, — sometimes  very  small 
indeed, — and  all  are  parasites.  The  difference  between  the  pre- 
vious and  the  present  family  is  in  the  venation,  and  is  not  easily 
made  out,  except  by  the  special  student  ;  nor  from  a  practical 
stand-point  is  the  matter  an  important  one.  It  is  among  the 
members  of  this  family  that  we  find  many  of  the  minute  creatures 


Long-tailed  Ophion,  Ophwn  tnaciinum,  and 
larva. 


PROPEBTY 


ur 


THE    INSECT   ifD^LD.  383 


that  infest  aphids.  If,  at  any  time  during  the  summer,  a  leaf 
badly  infested  with  plant-lice  be  examined,  there  will  be  usually 
found  a  few  specimens  that  seem  abnormally  swollen  and  livid 
gray  in  color  rather  than  green  or  yellow.  Such  specimens  are 
parasitized,  and  if  they  be  removed  to  a  closed  vessel,  there  will 
be  found  in  it,  in  a  few  days,  minute  blackish  or  brown  wasp-like 
creatures,  and  on  each  of  the  infested  plant-lice  will  be  seen  a  little 
round  hole,  which  shows  where  the  insect  emerged.  They  are 
usually  examples  of  minute  Braconids,  and  are  the  most  im- 
portant of  those  natural  checks  that  prevent  the  increase  of  plant- 
lice  above  a  certain  point.  Unfortunately,  that  point  does  not 
coincide  with  the  limit  at  which  the  insects  become  injurious  to 
the  farmer  ;  hence,  though  the  parasites  accomplish  their  pur- 
pose, they  do  not,  therefore,  confer  any  direct  benefit  upon  him. 
At  almost  all  periods  during  the  season,  but  especially  late  in 
summer  or  fall,  caterpillars  may  be  seen,  bearing  upon  their 
backs  and  sides  white  or  yellowish,  egg-shaped  bodies.  These 
are  often  supposed  to  be  the  eggs  of  the  caterpillars,  but  as  a 
matter  of  fact  they  are  cocoons  of  Microgaster  or  Apayiteles, 
little  parasites  belonging  to  this  family  ;  and  if  the  caterpillar  be 
confined  for  a  few  days  it  will  be  noticed  that  from  the  tips  of 
each  of  these  egg-shaped  bodies  a  little  circular  lid  is  lifted  off 
and  a  Httle  wasp  emerges.  If,  late  in  summer,  a  number  of  the 
large  sphinx  caterpillars  infesting  potato  or  grape-vines  are 
watched  when  they  yet  show  no  signs  of  infestation,  one  may  fre- 
quently see  the  little  larvae  boring  their 
way  through  the  skin,  wriggling  until  '^'• 

they  have  emerged  for  more  than  half 
their  length,  and  it  is  then  easy  to 
watch  the  formation  of  the  small  silken 

,-p,,  ...  ,  Sphinx  larva  covered  with  iSIi- 

cocoons.     The  caterpillar  soon  becomes  crogaster  zo<,oor.^. 

an    odd-looking  sight,  with    anywhere 

from  a  dozen  to  fifty  or  even  a  hundred  of  these  little  maggots, 
all  engaged  in  spinning  cocoons,  projecting  from  it  in  every  di- 
rection. The  egg-like  cocoons  are  attached  merely  by  a  Httle 
point,  so  that  they  may  be  easily  removed.  But  the  caterpillar 
has  been  drained  of  its  strength  and  of  the  substance  for  the  for- 
mation of  the  future  butterfly  :  it  collapses  and  dies,  unable  to 
complete  its  transformation  to  the  pupal  stage. 


384  AN  ECONOMIC  ENTOMOLOGY. 

Most  of  these  parasites  have  the  disadvantage  of  not  influ- 
encing in  the  least  the  amount  of  injury  done  by  the  host ;  they 
simply  prevent  it  from  changing  to  an  adult.  It  often  happens 
that  spinning  caterpillars  even  complete  their  cocoon,  and  in  this 
we  find  the  mass  of  parasitic  cocoons  instead  of  the  Lepidopter- 
ous  pupa.     On  the  other  hand,  some  of  them  complete  their 

Fig.  442. 


Apcuiteles  species. — Little  mass  of  cocoons  on   leaf,  replacing  an   infested  larva;   a 
single  cocoon  below,  from  which  adult  has  issued  ;  much  enlarged. 

development  and  kill  the  caterpillar  before  it  is  much  more  than 
half-grown.  Many  of  these  cocoon-forming  species  belong  to 
the  genus  Microgaster,  and  they  are  typical  of  a  very  large 
series  in  the  family.  The  plant-lice-infesting  forms  frequently 
belong  to  the  genus  Aphidius.  As  in  the  previous  family,  many 
of  these  insects  have  an  external  ovipositor. 

While  the  preceding  series  of  parasites  contain  a  very  fair  pro- 
portion of  large  species,  the   next  family,  Chalcididce^   contains 


THE    INSECT   WORLD.  385 

very  i&\\,   except  small  forms,  which  are  quite   usually  metallic 

black,  bronze,  or  green.    The  wings  are  without  venation,  except 

for  a  strong  vein  running  parallel  to  the  costal  margin,  but  not 

reaching  quite  to  the  tip,  and 

the  antennae   are   geniculated  Fig.  443. 

or  abruptly  bent  at  the   end 

of  the  long  first  joint.     Few 

of  these  have   the  ovipositor 

visible,  and  usually  it  lies   in 

a   groove  on  the   under   side 

of  the   tip   of  the   abdomen, 

issuing  before  the  apex.   These 

Chalcidid  flies  are  exceedingly 

.   .  Apheltnus    ntvMaspidis,    parasite    on    scale 

numerous,  and  are  parasitic  on  insects ;  much  enlarged. 

a  great  variety  of  other  insects. 

They  are  rather  more  robust  in  build  than  the  other  small  para- 
sites, and  this  fact,  with  their  usually  brilliant  metallic  coloration, 
is  a  tolerably  good  guide  to  the  family,  of  which  the  species  in- 
festing the  common  cabbage  butterfly  may  serve  as  a  good 
example.  If,  early  in  the  spring,  a  large  number  of  chrysalids 
of  the  cabbage  butterfly  be  collected, — which  can  be  easily  done 
along  the  fences  bordering  last  year's  cabbage-field, — it  will  be 
found  that  some  of  them  have  a  rather  warm  gray  color  and 
move  the  joints  of  the  abdomen  freely,  evidently  showing  life. 
Others  will  have  a  peculiar,  dead,  straw-yellow  color,  and  the 
abdomen  is  brittle  and  will  break  rather  than  move.  If  it  does 
break,  the  interior  of  the  chrysalis  will  be  found  completely  filled 
with  little,  greenish-gray,  maggot-like  larvae,  in  which  the  seg- 
ments are  well  marked  and  a  little  darker  in  color.  If  such 
infested  chrysalids  be  removed  to  a  warm  room  and  kept  in  a 
covered  vessel,  there  will  emerge  in  due  time  dozens  of  Ptero- 
mains  pKpariun,  a  greenish-bronze  Chalcidid,  instead  of  the 
common  white  cabbage  butterfly. 

Though  these  insects  are  minute,  being  scarcely  one-eighth  of 
an  inch  in  length,  yet  they  are  giants  compared  with  others 
which  live  in  scales  and  even  in  the  eggs  of  other  insects.  Very 
frequently  such  Chalcidids  are  bred  from  galls,  and  they  are  here 
either  parasitic  upon  the  actual  gall-maker,  or  they  may  live  in 
the  abnormal  tissue  produced  by  the  Cynipid  larvae.     We  find 

25 


386 


AN  ECONOMIC  ENTOMOLOGY. 


the  little  fellows  everywhere,  infesting  almost  all  kinds  of  insects, 
and  undoubtedly  they  do  much  to  prevent  the  increase  of  injuri- 
ous species.  Especially  is  this  true  of  those  ovipositing  in  eggs 
of  other  forms,  for  they  are  then  "nipped  in  the  bud,"  so  to 
speak.  Their  work  in  the  destruction  of  scale  insects  is  also  of 
great  importance,  and  frequently  we  find  on  a  scale-infested  tree 
a  large  proportion  with  little  round  holes,  showing  where  a  para- 


FiG.  445. 


Fig.  444. 


Trichogramma  pretiosa,  a  parasite  in   insect  eggs ; 
dot  may  represent  natural  size. 


Female    Isosoma  oviposit- 
ing in  stem  of  wheat. 


site  has  emerged.  It  is  a  pity  that  in  a  family  so  generally  useful 
we  should  find,  exceptionally,  some  injurious  species  ;  but  there 
is  no  doubt  that  members  of  the  genus  Isosoma  lay  their  eggs  in 
the  stems  of  grasses,  including  wheat,  and  the  larvae,  working  as 
they  do  in  the  joints,  have  received  the  name  "joint-worms." 
The  stem  hardens  where  the  larva  punctures  it,  and  this  inter- 
feres with  the  nourishment  of  the  plant  above  that  point,  les- 
sening or  entirely  preventing  the  formation  or  maturing  of  the 
grain.  There  is  but  a  single  annual  brood  of  these  insects,  and 
the  winter  is  passed  in  the  straw,  from  which  the  adults  emerge 
in  spring.  In  localities  where  this  insect  is  sufficiently  abundant 
to  make  it  necessary  to  use  remedial  measures,  the  utilization  of 


THE    IXSECT   WORLD. 


387 


the  straw  during  the  winter  will  check  injury  to  a  j^reat  extent. 
It  is  certain  that  some  near  allies  of  Isosoma  and  perhaps  some 
other  genera  of  Chalcidids  are,  at  least  in  jjart,  vegetarians  ; 
but,  so  far  as  I  am  aware,  none  other  has  proved  in  any  true 
sense  of  the  word  injurious  to  cultivated  crops.  Hence,  although, 
especially  in  the  central  and  western  parts  of  the  United  States, 

l'"iG.  446. 


Isosoma  tiitici. — a,  b,  larva  ;  /,  atlult  female  ;  .c  fore-wing  :  h,  hind  wing ;  other  letters 
are  structural  details. 


the  "joint-worm"  may  do  some  damage,  yet  it  is  so  easily  con- 
trolled that  it  scarcely  affects  the  value  of  the  family  as  a  whole. 

The  smallest  of  all  our  parasitic  insects  belong  to  the  family 
Proctotrypidce ,  and  even  the  largest  of  them  would  be  ordinarily 
considered  as  small  insects.  Among  them  we  find  the  greatest 
number  of  ^^^  parasites.  As  compared  with  the  Chalcidids, 
these  insects  are  rarely  metallic  in  color,  usually  black  or  brown, 
sometimes  yellow,  and  much  more  slender  in  build  ;  the  body  longer 
in  proportion  to  the  thickness.  Their  habits  may  be  said  to  be  in 
general  like  those  of  the  other  parasites,  and  they  are  not  easily 
distinguished  from  them,  except  by  the  special  student ;  but  they 
rarely  have  the  geniculated  antennae  described  for  the  Chalcidids. 
None  of  these  Proctotrypids  are  injurious,  so  far  as  we  know,  or 
feed  on  vegetable  matter,  though  sojne  are  found  in  galls,  appar- 
ently parasitic  upon  the  original  gall-maker. 

Taken  as  a  whole,  the  parasitic  Hymenoptera  belonging  to 


388  AN  ECO XO MIC  ENTOMOLOGY. 

the  various  families  heretofore  mentioned  constitute  one  of 
nature's  means  of  keeping  within  bounds  the  insects  of  other 
orders,  and,  indeed,  the  various  parasites  themselves.  Not  only 
are  the  little  creatures  parasites  upon  almost  all  other  insects, 
but  as  a  matter  of  fact  they  are  parasitic  even  upon  each  other, 
or  hyperparasitic,  so  that  it  is  a  clear  case  of  "dog  eat  dog." 

Fig.  447- 


Ceiaphron  triticiim,  parasitic  in  wheat  plant-louse. 

They  undoubtedly  check  injurious  species,  but  also  each  other  ; 
in  this  way  preserving  a  balance  from  year  to  year  which  keeps 
all  the  forms  at  about  the  same  relative  level.  Of  course  the 
"  hyperparasites, "  as  the  forms  infesting  the  other  parasitic 
species  are  termed,  are  distinctly  injurious  from  the  agriculturist's 
stand-point ;  perhaps  even  more  so  than  the  forms  actually  feeding 
on  vegetation. 

The  question  of  making  economic  use  of  parasites  belonging 
to  this  order  has  been  frequently  discussed,  but  no  practical 
results  have  yet  been  obtained.  Occasionally  several  species 
attack  a  single  host,  and  yet,  withal,  they  seem  to  produce  no 
effect  upon  it  in  the  long  run.  Even  though  we  may  breed  out 
of  a  lot  of  caterpillars  more  parasites  than  butterflies  or  moths,  in 
the  season  following  the  caterpillars  will  be  just  as  abundant  as 
they  were  the  year  before.     Just  where  the  checks  to  parasite 


THE    INSECT   WORLD. 


589 


increase  come  in  is  not  entirely  clear  in  all  cases.  Take,  for 
instance,  the  cabbage  butterfly  already  spoken  of.  I  have,  in 
collecting"  chrysalids  in  spring,  found  scarcely  one  in  twenty  that 
was  living,  and  from  which  I  obtained  a  butterfly.  All  the  others 
produced  parasites,  chiefly  the  little  Chalcidid  already  spoken  of: 
hundreds  of  them  for  every  butterfly  !  It  would  seem,  then,  as 
if  there  were  parasites  enough  here  to  attack  every  caterpillar 
that  hatched  from  the  eggs  of  this  first  brood  ;  yet  somehow 
they  seem  to  be  almost  entirely  free,  and  the  butterflies  increase 
normally  until  after  midsummer.  It  seems  almost  impossible,  in 
fact,  to  get  a  parasitized  larva  until  August  or  September,  and  not 
until  we  get  the  last  brood  of  caterpillars  do  the  parasites  seem  to 
resume  activity,  after  all  the  injury  has  been  done  to  the  cabbage 
crop.  Perhaps  ninety  per  cent,  of  all  the  caterpillars  will  be 
found  infested  at  this  time,  and  a  mere  fragment  of  the  brood 
comes  to  maturity  the  following  spring. 

We  are  unfamiliar  with  the  complete  life  history  of  most  of 
these  little  species,  and,  indeed,  a  great  many  yet  remain  to  be 
described.  It  would  be  rash  to  say  that  we  can  never  use  them 
for  our  own  purpose, — that  is,  in  checking  injurious  species  ;  but 
if  so,  it  is  certain  that  we  must  know  very  much  more  about 
them  than  we  do  at  present. 

A  very  curious  creature  sometimes  found  flying  through  open 
woods  is  the  Pelecinus  polyturator,  for  which  the  family  Peleciii- 
idcE  has  been  established.     The  female  is  remarkable  for  the  length 
of   its   slender    abdo- 
men, each  of  the  joints  Fig.  448. 
being  almost  as  long 
as  the  head  and  body, 
and  the  entire  insect 
is    sometimes    nearly 
four  inches  in  length, 
the     abdomen     alone 
measuring  more  than 
three.     The   insect  is 
so  very   odd    and   so 
often    noticed   that   it 

is  mentioned  here  to  answer  a  frequently  asked  question  as  to 
its  character.     It  is  not  at  all  rare  in  some  localities,  but  its  habits 


Pehcinus  polyturator,  male  and  female. 


39° 


AN  ECONOMIC   ENTOMOLOGY. 


are  yet  unknown  to  us.      It  is  believed  to  be  parasitic,  but  upon 
what  sorts  of  species  no  one  has  yet  discovered. 

The  remainder  of  the  order  has  been  roughly  classed  as 
Aculeate,  or  "  stinging"  forms,  the  majority  of  the  species  being 
provided  with  an  ovipositor  modified  into  a  sting  like  that  of  the 
bee,  having  connected  with  it  a  more  or  less  well-developed 
poison-sac.  From  the  fact  that  the  sting  is  a  modified  ovipos- 
itor, or  egg-laying  tube,  it  follows  that  it  can  be  found  in  the 
female  only  ;  hence  the  males  of  bees  and  wasps  of  all  kinds 
have  not  the  power  of  stinging,  and  may  be  safely  handled.  The 
use  of  the  sting  varies  in  the  different  families,  and  this  subject 
will  be  further  spoken  of 

One  little  group  is  separated  off  under  the  title  "  Tubulifera," 
and  contains  the  single  family   Chrysididce,  bees  of  a  brilliant 
metallic  blue  and  green,  deeply  punctured  or  pitted,  and,  as  a 
whole,  of  rather  robust  build.     They  are 
iG.  44Q.  among  the  most  beautiful  of  all  the  Hy- 

inenoptera,  are  of  fair  size,  and  are  peculiar 
in  the  structure  of  the  abdomen,  which  is 
telescopic.  From  three  to  five  segments 
only  are  visible,  the  others  being  re- 
tracted, but  capable  of  a  tube-like  exten- 
sion, at  the  end  of  which  the  minute  sting 
is  situated.  They  have  been  called 
"cuckoo-bees"  from  their  habit  of  laying  eggs  in  the  nests  of 
other  solitary  bees  and  wasps.  The  larva  is  supposed  to  hatch 
before  the  true  owner  of  the  food  supply,  and  to  devour  the 
store,  leaving  the  other  hapless  baby  to  starve  to  death.  Eco- 
nomically, the  species  are  of  no  importance,  save  as  they  form  a 
check  to  the  increase  of  certain  other  bees  and  wasps. 

Few  insects  are  better  known  to  the  average  observer  than  the 
ants  that  are  found  everywhere  :  in  our  houses,  in  fields,  in 
woods,  in  the  ground,  under  stones,  in  trees,  in  roots,  and  in  all 
other  likely  and  unlikely  places.  They  are  abundant  in  temper- 
ate countries,  more  rare  to  the  northward,  but  become  veritable 
pests  by  their  enormous  numbers  in  the  tropics.  They  have 
many  peculiarities  of  habit,  and  their  development  is  remarkable 
in  certain  directions.  We  find  among  them  architects  and 
builders,  agriculturists,  masons,   tailors,  and  many  of  the  other 


THE    INSECT    WORLD. 


391 


trades  and  professions  are  represented.  We  find  communities 
governed  in  some  directions  despotically  by  a  queen,  yet  at  the 
same  time  forming  the  most  perfect  republic,  in  which  every  indi- 
vidual has  its  rights  firmly  established  and  absolutely  beyond  the 
control  of  the  nominal  head  of  the  colony.  We  have  organiza- 
tions that  make  war,  keep  slaves,  lay  in  stores,  and  provide  for 
contingencies  ;  they  seem  able  to  forecast  the  future  in  some 
directions  and  intelligently  provide  for  it.  In  other  words,  they 
offer  some  of  the  most  interesting  problems  that  can  possibly  be 
studied.  It  is  unnecessary  to  waste  words  in  describing  the  ap- 
pearance of  an  ant,  and  it  need  only  be  said  that  all  the  true 
ants  are  distinguished  from  the  other  Hymenoptej-a  by  the  posses- 
sion of  one  or  more  scales  or  nodes  on  the  petiole  or  stalk  of  the 
abdomen.  We  find  also,  in  this  series,  the  development  of  what 
are  known  as  "  neuters,"  or  workers,  —that  is  to  say,  female  indi- 
viduals in  which  the  sexual  characters  are  not  perfected,  which 
are  incapable  of  reproduction,  and  whose  function  in  the  nest  is 
simply  to  perform  the  mechanical  labor  necessary  to  keep  up  the 
colony.  These  workers  have  no  wings,  and  in  their  appearance 
and  the  relative  proportion  of  the  parts  they  frequently  differ 
considerably  from  their  parents.  There  are  sometimes  several 
forms  of  workers  found  in  nests,  differing  from  each  other  in  the 
development  of  certain  parts  for  special  purposes,  but  attention 
will  be  called  to  these  hereafter,  where  necessary.  Though  the 
ants  agree  in  their  general  habits  and  peculiar  social  organization, 
yet  no  less  than  five  different  families  have  been  recognized, 
based  upon  structural  characters,  principally  of  the  abdomen  and 
head. 

The  most  numerous  in  species  of  these  families,  containing 
most  of  our  common  forms,  is  the  Formicidce,  in  which  the 
petiole  is  formed  of  a  single  joint  only,  and  the  abdomen  is 
smooth,  without  constriction  between  the  segments.  In  this 
family  the  "queens,"  or  females,  have  no  sting.  They  build 
their  nests  in  all  sorts  of  localities.  We  find  them  commonly  in 
our  fields;  often  in  woods,  where  the  large  black  "carpenter 
ants' '  are  the  most  prominent  ;  while  some  occur  under  stones 
or  around  the  roots  of  trees.  It  would  be  easy  to  write  a  book 
on  ants  alone,  but  necessarily  our  notes  of  them  must  be  con- 
fined here  to  the  features  of  economic  importance.      And  first 


392 


AN   ECONOMIC   ENTOMOLOGY. 


let  us  have  their  general  life  history.      In  a  colony  of  ants,  how- 
ever large,  there  is   usually  a  single  "queen,"   or  female,   the 

nominal   head  of  the   estab- 
FiG.  450.  lishment,  and  she  attends  to 

the  business  of  laying  the 
eggs,  which  are  white,  cylin- 
drical, and  a  little  elongated. 
They  are  taken  in  charge  by 
the  workers,  cared  for,  and 
in  about  a  month — the  time 
varying  with  the  species — 
helpless  grubs  are  produced. 
These  are  carefully  tended 
and  fed,  because  absolutely 
unable  to  help  themselves, 
are  periodically  cleaned  and 
moved  about  from  place  to 
place  in  the  nest,  that  they 
may  have  the  proper  degree 
of  warmth  and  dryness  or 
moisture,  and  after  about  six 
weeks  of  this  coddling  they 
are  full  grown.  Then  they 
either  spin  an  oval  cocoon, 
in  which  they  change  to 
pupae,  or  change  directly 
without  forming  such  a  cov- 
ering. The  cocoons  are  cared 
for  as  tenderly  as  were  the 
larvae  themselves,  and  these 
are  what  is  usually  known  as 
' '  ants'  eggs. ' '  They  may  be 
found  at  midsummer,  or  thereafter,  in  almost  any  colony  of  ants, 
and  usually  in  the  upper  chambers  of  the  nest,  where  they  get  a 
full  supply  of  warmth  from  the  sun.  The  adults  hatch  from  these 
cocoons  late  in  summer,  and  at  once  take  part  in  the  work  of  the 
nest,  so  far  as  they  are  workers.  Of  the  latter  there  may  be 
two  forms,  known  as  "worker  minors,"  or  small  workers,  and 
"  worker  majors,"  or  large  workers,  each  with  different  duties. 


Cremastogaster  luteolata.  —  a,  b,  large 
worker  ;  c,  its  head  ;  d,  female  ;  e,  its  wing  ; 
/,  small  worker.     Family  Formicidce . 


THE    INSECT    WORLD. 


393 


There  are  also  two  kinds  of  winged  forms,  males  and  females, 
both  larger  than  the  workers,  and  the  females  considerably  larger 
than  the  males.  All  the  insects  work  their  way  down  to  the 
lower  levels  or  inmost  galleries  of  the  nest  on  the  approach  of 
cold  weather,  and  hibernate  in  the  adult  stage  in  a  dormant  con- 
dition. In  spring,  with  the  approach  of  warm  weather,  activity 
is  resumed,  and,  usually  some  time  during  the  early  part  of  the 
season,  on  a  particularly  bright,  warm  day,  the  newly  developed 
males  and  females  leave  their  old  home  and  "swarm."  By  this 
is  meant  that  they  leave  the  nest  in  which  they  were  hatched  and 
fly  about  for  a  short  time.  They  mate  soon  after,  and  are  then 
ready  to  start  colonies  of  their  own.  None  of  them  ever  get 
back  to  the  old  home,  and  if  they  do  not  succeed  in  founding  a 
"  hill,"  they  perish  in  the  course  of  a  day  or  two.  Exactly  how 
the  different  species  start  their  colonies  is  not  known,  but  in  some 
cases,  certainly,  the  impregnated  female  strips  off  her  wings  and 
starts  a  small  nest  in  some  convenient  place,  doing  the  best  she 
can  under  the  circumstances,  and  laying  only  a  few  eggs.  These 
she  brings  to  maturity,  and  they  are  usually  of  the  small  or 
"worker  minor"  type.  When  fully  developed,  these  relieve 
their  parent  from  further  mechanical  work,  increase  the  size  of 
the  nest,  and  gather  food  as  well  as  attend  the  young  that  are 
still  continually  hatching.  If  circumstances  favor,  the  nest  grows 
rapidly,  and  it  may  eventually  become  enormous  in  size,  con- 
taining millions  of  individuals,  and  ramifying  for  distances  that 
we  have  not  yet  succeeded  in  following  to  the  end.  The  life  cycle 
of  all  the  ants  has  not  been  definitely  determined  as  yet,  but 
' '  queens' '  have  been  kept  as  long  as  seven  years  and  workers  for 
three  or  four.  The  food  of  ants  is  variable, — sometimes  animal, 
sometimes  vegetable,  and  quite  usually  both.  The  same  species 
may  feed  upon  fragments  of  insects  and  other  animal  matter,  and 
also  upon  plant  tissue  of  various  kinds.  They  are  usually  fond 
of  liquid  food,  especially  if  it  is  sweet,  and  some  species  gather 
and  store  honey  like  the  bees,  although  in  quite  a  different  man- 
ner. In  the  more  temperate  parts  of  the  United  States  ants 
are  only  indirectly  injurious,  although  they  are  never  beneficial. 
There  is  quite  a  common  belief  that  ants  destroy  the  plant-lice 
among  which  they  are  frequently  found  ;  but  this  is  exactly  con- 
trary to  the  fact,  for  plant-lice  play  a  very  important  and  curious 


394 


AiV  ECONOMIC  ENTOMOLOGY. 


part  in  the  economy  of  certain  species  of  ants.  As  we  learnt  in 
the  chapter  on  plant-Hce,  these  insects  are  furnished  with  a  pair 
of  honey-tubes  near  the  end  of  the  abdomen,  through  which  there 
is  excreted  a  sweet,  almost  transparent,  liquid,  of  which  the 
ants  are  very  fond.  In  many  cases  aphids  live  on  the  roots  of 
plants  during  the  whole  or  a  part  of  their  life,  and  such  species 
are  in  nearly  every  instance  carefully  tended  by  ants.  We  may 
find,  on  lifting  up  a  large  stone  at  the  foot  of  a  tree  near  the 
edge  of  a  wood,  that  all  the  little  rootlets  covered  by  it  are  clus- 
tered as  thickly  as  possible  with  plant-lice,  and  that  around  them 
the  earth  has  been  carefully  tunnelled  out  ;  in  other  words,  we 
have  the  roots  forming  part  of  the  nest  system  of  an  ant  colony. 
As  the  plant-lice  increase  in  number,  additional  roots  are  laid 
bare,  and  the  young  are  transported  to  them  that  they  may 
always  find  an  abundance  of  food.  In  return,  the  ants,  whenever 
the  desire  seizes  them,  call  upon  one  or  more  of  the  aphids,  and, 
by  touching  them  with  their  antennae,  induce  them  to  give  up 
a  drop  or  two  of  their  sweet  secretion.  Exactly  how  large  a 
proportion  of  the  food  of  the  ant  colony  this  kind  of  material 
forms  is  yet  undetermined  ;  but  certain  it  is  that  plant-lice  con- 
stitute a  very  important  element  in  the  supply  of  some  species, 
and  fully  represent  our  cattle  for  all  ant  purposes. 

Little  brown  ants  about  three-sixteenths  of  an  inch  in  length 
occur  very  abundantly  in  the  fields  throughout  almost  all  parts 
of  our  country,  building  small  underground  nests.  These  ants 
belong  usually  to  the  genus  Lasius,  and  may  be  found,  especially 
early  in  the  year,  on  the  leaves  of  all  sorts  of  plants  infested  by 
aphids.  In  melon  and  sweet  potato  fields  they  are  often  ex- 
tremely abundant,  and  it  is  more  than  likely  that  they  are  active 
in  transporting  from  one  plant  to  another  the  lice  infesting  these 
particular  crops.  Of  the  Lasius  bnnineus,  we  know  that  it  tends 
the  corn-root  louse,  gathering  the  young  larvae  in  the  fall  and 
preserving  them  during  the  winter  safe  beyond  the  reach  of  any 
natural  enemies,  colonizing  them  in  spring  upon  the  roots  of  corn 
plants.  Indirectly,  therefore,  these  ants  are  decidedly  injurious 
through  their  relation  to  the  plant-lice.  Other  species  gather 
plant-lice  eggs  and  care  for  them  during  the  winter,  colonizing 
the  young  upon  proper  food  plants  in  spring. 

We  find  certain  other  species  making  their  hills  in  our  lawns 


THE    INSECT    WORLD.  395 

and  gardens,  or  in  grass-plots,  and  they  are  sometimes  decidedly 
troublesome  in  such  localities.  Where  this  occurs,  there  is  noth- 
ing better  for  getting  rid  of  them  than  bisulj)hidc  of  carbon.  Pour 
a  quantity  into  each  of  the  openings  of  the  disk  or  hill,  closing 
them  up  by  stepping  on  each  as  it  is  treated.  The  fumes  will 
penetrate  the  chambers  in  every  direction,  and  if  a  sufficient 
amount  has  been  used,  will  kill  not  only  all  the  adults,  but  all 
larvee  as  well.  A  single  application  is  usually  all  that  is  necessary  ; 
but  in  a  very  large  colony  it  may  sometimes  happen  that  the 
farther  chambers  are  not  reached  by  the  fumes,  and  that  the  nest 
reappears  near  by  ;  rarely  in  the  old  spot.  When  that  occurs,  a 
second  treatment  is  tolerably  certain  to  be  effective.  It  has  been 
recommended  that,  to  get  the  best  results,  holes  be  poked  with  a 
stick  into  different  parts  of  the  hill,  but  I  have  not  found  this  of 
any  great  advantage.  It  has  also  been  recommended  that,  after 
pouring  a  considerable  quantity — say  three  or  four  ounces — into 
the  main  opening  of  the  nest,  the  vapor  be  exploded  by  means 
of  a  match  held  at  the  end  of  a  stick.  When  this  is  done  the 
nest  is  completely  wrecked,  and  the  poisonous  vapor  is  forced  to 
every  portion  of  the  galleries,  so  that  escape  is  almost  impossible  ; 
while  larvae  and  pupae  are  buried  so  thoroughly  that  they  can 
never  make  their  way  to  the  surface,  even  if  not  killed  by  the 
fumes.  This  is  a  very  good  method  where  a  large  nest  is  to 
be  dealt  with  ;  but  whoever  attempts  it  must  remember  that  the 
vapor  of  the  bisulphide  is  exceedingly  inflammable,  and  must 
make  certain  that  he  is  far  enough  from  the  opening  of  the  nest 
to  prevent  being  caught  by  the  flash.  Ants  are  never  desirable 
in  a  cultivated  field  ;  they  have  no  business  there,  and  are  cer- 
tainly of  no  benefit  to  the  farmer,  even  if  they  do  not  directly 
feed  upon  plant  tissue. 

Wherever  the  corn-root  louse  is  injurious,  late  fall  ploughing 
should  be  practised  to  destroy  the  nests  of  the  ants.  If  the 
ploughing  be  done  before  the  ants  have  gone  into  winter-quarters, 
they  will  either  build  a  new  nest  sufficient  for  their  purpose,  or 
will  move  with  their  belongings  to  a  spot  in  which  they  are  able 
to  winter  ;  so  no  good  will  be  accomplished.  If  the  ploughing 
be  deferred  until  frosty  nights  and  cool  days  discourage  activity, 
the  ants  will  be  unable  to  repair  damages,  or  will  not  have  suffi- 
cient time  to  re-establish  themselves  before  they  become  torpid. 


396 


AN  ECONOMIC  ENTOMOLOGY. 


The  ploughing  should  be  deep  and  as  thoroughly  done  as  pos- 
sible, so  as  to  not  only  disturb  and  break  up  the  nests  com- 
pletely, but  to  scatter  the  plant-lice,  eggs,  or  other  material  that 
the  ants  may  have  gathered.  By  this  simple  means  injury  may 
frequently  be  prevented  during  the  year  following. 

Incidentally  it  has  been  mentioned  that  some  species  of  ants 
gather  honey  and  store  it  ;  and,  curiously  enough,  instead  of 
building  cells  for  its  reception,  as  do  the  bees,  a  special  form  of 

Fig.  451. 


Honey-ants,  Myrmecocystus  melliger,  filled  with  honey. 


worker  is  developed,  with  an  unusually  elastic  crop  and  abdo- 
men. These  specimens  are  simply  stuffed  by  the  other  workers 
until  they  become  of  the  size  of  a  small  cherry,  utterly  helpless 
and  incapable  of  motion.  In  this  condition  they  cling  to  the 
walls  of  the  nest  until,  in  the  course  of  time,  their  stock  is  used  up, 
when  they  again  resume  activity. 

Three  of  the  other  ant  families  to  which  reference  has  been 
made  contain  no  species  of  particular  interest  to  the  farmer,  how- 
ever interesting  they  may  be  to  the  student. 

But  in  the  family  AlyrmicidcE  we  again  find  species  that  are 
numerous  and  of  more  or  less  importance  to  man.  Here  the 
petiole  of  the  abdomen  is  two-jointed,  differing  thus  from  the 
other  important  family,  FormicidcE.  Many  of  the  species  have 
the  sting  well  developed  in  workers  and  "  queens,"  and  are  for- 
midable creatures  by  reason  of  this  weapon  ;  but  not  all  our  forms 
are  so  furnished,  as  is  known  by  those  who  have  suffered  from  an 
invasion  of  small  red  ants  in  houses.  This  little  creature,  Mono- 
morhtm  pharao)iis,  sometimes  occurs  in  myriads,  and  nothing  is 


THE    INSECT    WORLD. 


397 


safe  from  it.  Sue^ar  is  especially  attractive,  but  almost  anything 
is  attacked,  nothing  more  readily  than  a  bone  from  which  the 
meat  has  been  roughly  scraped,  and  which  is  yet  a  little  bloody. 
It  seems  impossible  to  get  rid  of  these  creatures,  because  they 
avoid  poisoned  food  and  anything  that  has 
the  appearance  of  a  trap.     A  few  specimens  I'u;.  452. 

may  be  killed,  but  very  soon  the  character 
of  the  mixture  is  recognized,  and  it  is  left 
untouched.  "  Insect-powder"  — pyrethrum 
— is  effective,  but  it  is  practically  impossible 
to  get  it  everywhere,  and  the  ants  simply 
avoid  it.  Carbolic  acid  and  naphthalene  are 
both  useful  as  repellents  :  the  insects  dislike 
th'e  odors  intensely,  and  will  not  approach 
these  materials  ;  but  while  certain  closets  may  Monomorium pharaoms. 
be  protected  in  that  way,  the  odors  are  not 
particularly  desirable  near  food  products,  and  are  as  repugnant 
to  many  persons  as  they  can  possibly  be  to  the  ants  them- 
selves. The  simplest  method,  perhaps,  is  mechanical  destruc- 
tion, as  follows  :  Where  meat  is  used  every  day,  the  bones,  or 
some  of  them,  should  be  cut  out  before  it  is  cooked  and  placed 
in  a  main  line  of  insect  travel.  When  they  become  thoroughly 
covered  with  hundreds  or  even  thousands  of  ants,  the  whole  mass 
should  be  thrown  into  the  fire.  If  this  process  is  repeated  two 
or  three  times  a  day,  a  few  days  in  succession,  the  ants  seem  to 
be  seized  with  a  panic,  and  usually  abandon  the  house  com- 
pletely. Instead  of  bones,  a  sponge  dipped  in  sugar  water  and 
loosely  pressed  out  may  be  used  ;  or,  better  yet,  there  should  be 
two  sponges.  The  sweetened  one  should  be  placed  where  the 
ants  run,  and  the  news  of  its  presence  will  spread  throughout  the 
entire  house  in  a  remarkably  short  time.  When  the  first  sponge 
is  entirely  filled  with  ants,  the  second  should  be  prepared  in  the 
same  way  to  replace  the  first,  which  is  to  be  taken  up  and  put 
into  boiling  water.  This  destroys  the  insects  at  once,  and  the 
sponge  can  be  washed  out,  again  dipped  in  the  sugar  water,  and 
used  to  replace  sponge  number  two  when  that  is  filled  with  in- 
sects. Here  the  same  effect  is  obtained  :  the  insects  are  seized 
with  terror,  and  seem  to  realize  the  presence  of  a  force  that 
they  do  not  understand.    The  sudden  lessening  of  their  numbers 


398  AN  ECONOMIC   ENTOMOLOGY. 

strikes  them  with  such  horror  that  they  abandon  not  only  their 
nest  but  the  house  itself.  I  have  myself  used  this  method  on 
two  occasions,  and  have  recommended  it  frequently  to  others  ; 
in  every  case  with  the  best  results. 

To  this  family  belong  the  so-called  "agricultural  ants"  of 
Texas  and  the  Southwest,  some  species  also  occurring  in  Florida 
and  other  parts  of  the  Southern  United  States.  These  build  im- 
mense underground  nests,  and  keep  on  the  surface  a  cleared 
space  varying  in  diameter  according  to  the  size  of  the  colony. 
They  cultivate  grasses  on  these  plots,  of  the  seeds  of  which  they 
are  especially  fond,  and  which  they  store  in  their  galleries.  Their 
food,  in  fact,  consists  mainly  of  seeds  of  various  descriptions, 
and  these  they  gather  from  whatever  plants  there  may  be  in  the 
vicinity.  The  insects  are  very  abundant  in  some  localities  and 
are  great  nuisances  in  cultivated  fields,  not  so  much  from  what 
they  actually  destroy  by  eating,  but  from  the  fact  that  they  tol- 
erate nothing  in  their  vicinity  except  what  suits  them.  They 
have  no  particular  use  for  corn  or  cotton,  and  ruthlessly  cut 
down  every  stalk  that  encroaches  on  their  domain.  The  only 
substance  that  has  been  employed  against  them  with  any  degree 
of  success  is  bisulphide  of  carbon,  and  this  should  be  used  in 
quantities  depending  upon  the  size  of  the  nest.  In  these  cases 
the  vapor  should  be  exploded  in  order  to  produce  the  best  re- 
sults. The  nests  extend  for  so  long  a  distance  underground  that 
the  insects  will  not  be  reached  otherwise,  and  when  the  material 
has  entirely  evaporated,  the  galleries  are  again  useful  to  them. 
On  the  other  hand,  the  explosion  shatters  the  entire  nest,  and 
the  insects  that  escape  in  remote  galleries  are  not  likely  to  start 
again  on  the  same  soil,  unless  the  queen  also  has  escaped.  It 
has  been  already  indicated  that  such  a  nest  is  a  complicated  or- 
ganization. It  contains  not  only  its  owners  with  all  their  races 
and  castes,  but  frequently  also  slaves, — other  species  of  ants  that 
have  been  conquered  and  stolen  while  in  the  larval  or  pupal 
state,  and  which  now  perform  all  or  a  great  portion  of  the  manual 
labor  of  the  colonies.  It  often  contains  also  not  only  plant-lice, 
but  coccids,  which  are  cared  for  in  the  same  way,  and  occasion- 
ally other  species  of  Homoptera,  such  as  tree-hoppers.  We 
find,  in  addition,  numerous  species  of  insects  that  seem  to  take 
the  part  of  guests.     Some  of  these  are  scavengers,  and  they  evi- 


THE    INSECT    WORLD. 


399 


dently  keep  the  nest  clean  and  remove  decaying  particles  ;  others 
may  be  of  some  use  to  the  ants  by  excreting  certain  sweet  sub- 
stances which  induce  their  toleration  ;  while  yet  others  have  no 
use  at  all,  so  far  as  we  can  discover.  Such  are  certain  crickets 
which  are  always  found  associated  with  ants,  and  certain  cater- 
pillars. What  functions  these  insects  have  in  the  anthills  is  as 
yet  somewhat  obscure. 

In  the  tropics  there  are  species  that  occasionally  change  their 
camps,  and  are  known  as  foraging  ants.  When  the  whim  seizes, 
or  unknown  causes  determine  them,  they  leave  their  nest,  bag 
and  baggage,  attended  by  all  the  insects  that  lived  with  them, 
and  start  upon  a  march  straight  forward,  destroying  everything 
that  attempts  to  prevent  their  passage.  A  house  or  a  village  is 
no  barrier  ;  they  pass  through  or  over  it,  destroy  every  living 
thing  it  contains,  and  devour  all  the  provisions.  The  inhab- 
itants of  countries  subject  to  these  foraging  expeditions  soon 
learn  to  recognize  their  character,  and  immediately  seek  safety 
in  flight.  The  ants  continue  their  march,  and  soon  the  house 
or  village  can  be  reoccupied,  with  the  certainty  that,  if  all  the 
provisions  have  been  cleared  out,  so  also  have  all  the  vermin  : 
rats,  mice,  snakes,  roaches,  and  similar  creatures  being  all  killed 
and  eaten. 

The  battles  of  ants  have  been  described  by  more  than  one 
author  ;  but  as  this  is  the  function  of  another  kind  of  work, 
nothing  more  will  be  said  here  about  these  very  interesting 
creatures. 

Next  in  the  orderly  series  come  the  Fossores,  or  "digger- 
wasps."  Here  the  two  normal  sexes  only  are  developed,  and 
they  are  solitary, — that  is,  they  never  form  communities.  They 
often  build  their  nests  underground,  preferring  sandy  spots  ;  but 
the  families  vary  much  in  this  respect.  The  females  are  always 
provided  with  a  sting,  which  they  use  on  slight  provocation,  and 
they  differ  from  the  next  family  of  true  wasps  by  having  the 
wings  always  flattened  and  never  longitudinally  folded  in  repose. 
Sometimes,  instead  of  burrowing  underground  to  form  their  cells, 
they  use  the  stems  of  pithy  plants  like  alder  and  sumach,  and 
often  nests  are  built  of  mud,  in  sheltered  localities  against  houses, 
barns,  or  other  convenient  places,  or  even  attached  to  twigs  or 
shrubs. 


400 


A.V  EC 0X0 MIC  ENTOMOLOGY. 


Fig.  453- 


A  velvet  ant,  Splicer 
ophthalma  occiden 
talis. 


Occasionally  we  find,  running  on  sandy  spots,  an  insect  that 
looks  like  a  large  ant,  very  prettily  colored  and  banded  with 
bright  scarlet  and  black,  rusty  red  or  mottled  yellow.  If  one  of 
these  apparent  ants  be  picked  up,  the  result 
is  usually  a  surprise  in  the  form  of  an  enor- 
mously long  sting,  for  we  really  have  a  wing- 
less "digger-wasp,"  which  from  its  appear- 
ance and  habits  has  been  called  a  "velvet 
ant."  Just  what  the  breeding  habits  of  these 
Mutillidce  are  is  not  known,  but  they  are  sup- 
posed to  be  parasites,  or  at  least  to  lay  their 
eggs  in  the  nests  of  other  species  of  Hymen- 
optera.  There  is  considerable  difference  be- 
tween the  sexes,  and  the  males  are  winged 
even  when  the  females  are  wingless,  the  wings 
being  usually  blackish  in  color. 

Another  series  of  "diggers"  belongs  to  the 
family  Scoliidce,  and  these  may  often  be  seen 
quite  early  in  the  spring,  flying  close  to  the 
surface  of  the  ground,  with  a  buzzing  noise.     Often   they  are 
found  visiting  flowers,  particularly  the  males,  which  are  some- 
times quite  abundant  when  raspberries  are  in  bloom.     These  in- 
sects, so  far   as  we   know 
Fig.  454.  their  habits,  lay  their  eggs 

in  underground  larvae, 
which  are  then  devoured 
by  the  young  of  the  wasp. 
The  common  "white 
grub,"  the  larva  of  Lack 
nosterna,  is  subject  to  the 
attacks  of  one  of  these 
species,  Tiphia  inornata, 
a  black  wasp,  rather  sparingly  clothed  with  fine  white  hair,  and 
sometimes  attaining  the  length  of  three-fourths  of  an  inch  ;  and 
there  are  others  that  attack  our  injurious  underground  species  of 
all  orders. 

In  the  family  Pompilidce  we  have  a  series  of  rather  stout, 
black  forms,  quite  frequently  banded  with  red  on  the  abdomen, 
while  sometimes  the  entire  insects  are  more  or  less  red.     They 


White-grub  parasite,  Tiphia    inornata. — a,  ima 
go;  b,  head  of  larva;  c,  larva;  rf,  cocoon. 


THE    INSECT    WORLD. 


401 


usually  have  a  velvety  appearance,  or  look  as  if  they  were  cov- 
ered with  a  whitish  bloom,  and  the  wings  are  also  either  black  or 
yellow,  like  the  prevailing  colors  of  the  body.  They  lay  their 
eggs  in  spiders,  which  they  bury,  and  in  which  the  larvae  de- 
velop. Perhaps  this  is  a  good  place  to  mention  the  fact  that 
these  digger-wasps  make  use  of  their  stings  and  the  poison  se- 


IMC.    455 


Pepsi's  forntosiis,  tarantula-hawk. 

creted  by  them  for  preserving  from  decay  and  in  a  condition 
suitable  as  food  for  their  young  the  larvae,  spiders,  and  other 
insects  upon  which  they  feed.  They  sting  their  prey  very  care- 
fully, in  such  a  way  as  to  paralyze  and  render  it  motionless, 
while  yet  it  does  not  die  ;  and  the  larvae,  when  they  hatch,  begin 
feeding  very  carefully,  so  as  not  to  kill  their  host  until  they  them- 
selves are  sufficiently  developed.  The  poison  introduced  seems 
to  simply  suspend  life,  or  rather  allows  it  to  go  on  without  a 
waste  of  tissue.  Spiders  of  all  kinds  are  attacked,  and  even  the 
fierce  tarantula  of  the  South  and  Southwest  has  its  enemy  in  an 
enormous  species  o{ Pepsis  known  as  the  "  tarantula-hawk." 

Perhaps  the  most  common  forms  belonging  to  this  series  are 
those  in  which  the  abdomen  ends  in  a  small  bulb-like  structure 

26 


402  AN  ECONOMIC  ENTOMOLOGY. 

connected  with  the  thorax  by  means  of  a  long  stalk  or  pedicel. 
These  belong  to  the  family  Sphecida,  of  which  the  majority 
build  their  nests  underground  and  provision  them  with  spiders, 
caterpillars,  or  other  larvae.  Others,  known  as  "  mud-daubers," 
species  of  Pelopceus,  plaster  their  nests  against  out-houses,  in  all 

sorts  of  corners  and  under  all  sorts  of 
shelters.  They  are  sometimes  built 
singly,  but  usually  in  groups,  and  may 
consist  of  either  a  shapeless  mass  of 
mud,  or  may  be  regularly  arranged, 
often  with  ribbed  sides.  The  insects 
that  build  these  nests  are  either  metal- 
lic blue,  or  black  marked  with  yellow, 
and  here  the  pedicel  connecting  the 
abdomen  with  the  thorax  is  unusually 
A  mud-dauber.  Peiopcus        ^        ^^^  slender.     The  mud  is  carried 

species.  "^ 

by  the  insect  with  its  forelegs  and  jaws, 
and  is  applied  carefully,  pellet  by  pellet,  to  the  nest,  until  the 
cells  are  completed.  Then  they  are  stored  with  some  one  kind 
of  insect  as  food  for  the  larva.  If  the  insect  begins  on  caterpillars, 
it  continues  to  collect  caterpillars,  all  of  the  same  species,  stinging, 
as  already  described,  so  as  to  paralyze  them,  and  then  packs 
them  away  in  the  cavity  as  closely  as  possible.  Finally,  when  a 
cell  is  full,  an  egg  is  introduced  ;  and  now,  when  the  young  wasp 
hatches,  it  finds  food  in  abundance  at  hand,  and  simply  lives  upon 
this  supply,  taking  one  caterpillar  after  another,  or  one  spider 
after  another,  as  the  case  may  be.  Some  small  species  store  their 
nests  with  plant-lice.  These  insects  are  to  be  considered  as  de- 
cidedly beneficial,  and  if  the  nests  are  sometimes  unsightly  and 
the  wasps  themselves  a  nuisance,  yet,  taken  all  in  all,  they  deserve 
encouragement.  The  number  of  caterpillars  destroyed  by  them 
in  the  course  of  a  season  is  enormous.  I  have  counted  thirty 
canker-worms  in  a  single  cell,  and  have  sometimes  opened  nests 
in  which  there  were  an  even  greater  number  of  small  Tortricid 
caterpillars.  Any  insects  which  destroy  as  many  caterpillars  as 
do  these  wasps  deserve  our  best  consideration  and  should  not 
be  wantonly  destroyed.  Another  peculiarity  to  be  noticed  in 
opening  the  nests  is,  that  the  insects,  whether  caterpillars  or 
spiders,  are  all  of  just  about  the  same  size,  as  if  the  mother  had 


THE    INSECT    WORLD. 


403 


exercised  great  care  in  portioning  out  the  food  to  the  best  ad- 
vantage. The  adults  may  often  be  found  on  flowers,  and  when 
the  golden-rod  is  in  bloom  in  late  summer,  some  of  our  largest 
and  most  attractive  species,  like  Sphex  ichneiimonea,  make  their 
appearance  in  great  abundance. 

The  allied  "diggers"  belonging  to  the  Larridcc  have  the 
abdomen  more  closely  joined  to  the  thorax,  and  provision  their 
nests,  which  are  made  underground,  with  small  grasshoppers. 
The  insects  are  not  nearly  so  common  or  so  numerous  in  species 
as  those  previously  mentioned,  and  are  chiefly  inhabitants  of  the 
more  southern  States. 

In  the  BenibecidcB  we  have  many  large,  brightly  colored  spe- 
cies, some  of  which  prey  upon  cicadas,  stinging  so  as  to  render 
them  helpless,  and  carrying  them  oft'  to  their  nests  as  provision 
for  their  young.  It  is  interesting  to  watch  a  specimen  of  Sphe- 
cms  speciosus  when  it  has  a  large  cicada  to  be  transported.  If 
the  insect  is  captured  and 

paralyzed  upon  a  tree,  the  ^^'  ^^'^' 

wasp  drags  it  along  the 
branch  to  some  convenient 
point,  and  from  it  flies  as 
directly  as  possible  towards 
its  nest.  Sometimes  its 
strength  is  not  sufficient  to 
sustain  the  weight,  and 
then  it  is  drawn  gradu- 
ally to  the  ground.  In 
such  case  it  again  drags  the 
insect  to  the  top  of  some 
convenient  shrub  or  tree, 
and  makes  another  eftbrt, 
again  flying  as  far  as  pos- 
sible before  allowing  itself 
to  be  pulled  down,  but  always  arranging  matters  so  that  it  is  able 
to  make  a  new  start  from  an  eminence.  In  other  words,  the  wasp 
is  often  unable  to  lift  the  cicada  from  the  ground  in  direct  flight, 
but  is  able  to  drag  it  to  an  elevation  sufficiently  great  to  fly  a  con- 
siderable distance  before  being  drawn  to  the  ground,  and  in  this 
way,  after  a  time,  it  manages  to  reach  its  nest.     These  Bembecids 


Sphecius  speciosus  carrying  a  cicada  to  its  home. 


404 


AN  ECONOMIC  ENTOMOLOGY. 


are  quite  numerous,  and  the  abdomen  is  conical  in  shape,  con- 
nected with  the  thorax  by  a  very  short  and  slender  neck,  or 
pedicel,  more  resembling  the  true  wasps  than  any  other  of  the 
species  that  we  have  been  considering. 

There  are  several  other  families  with  similar  habits,  differing  in 
appearance  to  some  extent,  and  varying  in  the  character  of  the 
insects  used  in  storing  their  nests.  Among  the  families  contain- 
ing the  smaller  species  we  find  those  types  that  burrow  in  pithy 
plants  and  prefer  small  insects  for  provisioning  their  nests  : — 
flies,  plant-lice,  and  small  spiders  being  the  most  usual  supplies. 

Taken  as  a  whole,  all  the  digger-wasps  are  useful  insects,  and 
they  require  for  food,  in  the  course  of  a  season,  a  very  large  num- 
ber of  specimens  injurious  to  plant-life. 

The  "true  wasps,"  or  Vespidce,  are  distinguished  from  the 
"diggers"  by  the  fact  that  the  fore-wings  are  folded  longitudinally 
when  at  rest,  and  this  is  a  character  easily  seen  and  quite  distinctive. 
We  have  among  them  solitary  and  social  forms, — the  solitary 
types  so  called  because  only  the  two  normal  sexes  are  present,  and 
because  they  do  not  live  in  colonies.  There  is  a  great  variation 
in  habit,  and  we  find  species  that  bore  in  woody  tissue,  some 
that  inhabit  pithy  plants,  some  that  burrow  in  the  earth,   and 

others  that  make  mud 
nests.  The  mud  nests 
vary  in  form  and  are 
often  quite  pretty,  those 
of  Eumenes  resembling 
a  jug  or  vase  attached  to 
the  twigs  and  stems  of 
plants.  It  is  not  always 
possible  to  distinguish  be- 
tween the  cells  and  nests 
of  the  diggers  and  those 
of  the  true  wasps,  and 
practically  it  is  a  matter 
of  no  importance,  because 
the  habits  of  the  insects  are  similar, — that  is,  they  store  their 
cells  with  insects  upon  which  their  larvae  feed.  All  solitary 
wasps  are  beneficial,  therefore,  and  should  be  encouraged  by  the 
farmer. 


c 

Fralenial  potter-wasp,  Enmrnes  fiatrrna. — a, 
wasp  ;  b,  its  cell  ;  c,  same  broken  open  to  show  the 
caterpillars  stored  in  it. 


I" ir..  458. 


I'lc.  4()i 


Kig.  458,  a,  .arvF.  ;  *,  c,  pupa,  from  beneath  and  side;  ,■,/.,<>■.  slructiiral  details,  o( 
Sfiheciits  speciosus.  FiR.  459,  larva  of  Sfihrriiis  sfircinsiis  fccdins  on  cicada  in  its  under- 
ground burrow.    Fig.  461,  nest  of  l/espa  inaailata,  just  started. 


THE    INSECT    WORLD.  405 

In  the  social  wasps  we  find  a  step  towards  the  organization 
found  in  a  beehive,  sometimes  well  and  sometimes  very  poorly 
marked  ;  i)ut  in  all  cases,  besides  typical  males  and  females,  there 
is  a  worker  caste,  which,  as  in  the  ants  and  bees,  is  composed  of 
sexually  undeveloped  females.  Briefly  stated,  the  history  of 
these  wasps  is  about  as  follows  :  Males  and  females  appear  in 
fall  ;  the  females  are  impregnated  and  live  through  the  winter  in 
such  shelter  as  they  are  able  to  find  ;  in  the  spring,  with  the  ap- 
proach of  warm  weather  and  the  opening  of  the  flowers,  the 
females  revive,  and  at  once  begin  reproducing  their  kind.  They 
start  a  small  nest  of  only  a  few  cells,  and  lay  eggs  in  them  as  soon 
as  they  are  well  started.  In  a  few  days  the  larvae  hatch;  the 
female  increases  the  size  of  the  cells  and  adds  to  them,  and  to  her 
other  duties  is  now  added  the  care  of  the  newly  hatched  young, 
which  must  be  fed  and  tended  daily.  In  three  or  four  weeks  the 
first  larvie  become  full-grown,  and  the  cells  are  then  capped  by 
the  mother.  In  this  closed  cavity  the  change  to  the  pupa  takes 
place,  and  in  due  time  an  adult  appears.  This  adult  is  a  worker, 
or  undeveloped  female,  and  at  once  begins  to  help  the  original 
mother  in  the  work  of  attending  to  the  brood  and  increasing  the 
size  of  the  nest.  Until  midsummer,  at  least,  workers  only  are 
produced  ;  but  then,  when  the  brood  of  workers  is  sufficient  to 
relieve  the  stem  mother  of  all  necessity  for  labor,  eggs  are  laid 
that  produce  sexually  complete  forms, — males  and  females, — which 
generally  issue  during  the  first  days  of  September.  The  old 
female  now  dies,  and  when  cold  weather  sets  in  the  workers 
and  males  also  succumb,  leaving  only  the  impregnated  new 
females  to  live  through  the  inclement  season.  Of  course  there 
are  many  modifications  of  this  general  life  history,  and  some  colo- 
nies become  very  much  larger  than  others.  In  some  instances 
the  cells  seem  to  be  used  over  and  over  again,  and  no  more  are 
manufactured  than  is  necessary  to  accommodate  the  brood.  In 
other  instances  it  seems  as  if  the  cells  are  used  only  once,  and 
new  ones  are  built  for  each  individual  larva.  The  locality  in 
which  the  nests  are  built  also  varies,  although  the  general  char- 
acter of  the  comb,  or  cell,  is  nearly  always  the  same.  As  a  home, 
some  species,  like  the  "  yellow-jackets,"  select  a  little  cavity  un- 
derground ;  some,  like  the  giant  Vespa  crabro,  a  hollow  tree  ; 
some  a  favorable  spot  among  the  branches.     Others  build  un- 


4o6  AN  ECONOMIC  ENTOMOLOGY. 

protected  combs  in  the  shelter  of  a  projectuig  ledge  of  rock,  or 
under  the  eaves  of  houses,  or  even  under  fence  boards  ;  while  yet 
others  build  their  globe-shaped  structures  openly  upon  bushes, 
and  these  are  usually  termed  "  hornets."  The  material  of  which 
the  nest  is  composed  is  a  sort  of  wood-pulp  paper.  The  insect 
scrapes  a  small  bit  of  wood-fibre  from  an  exposed  surface,  mixes 
it  with  saliva,  kneads  it  into  shape,  and  then,  by  means  of  the 
mandibles  and  forelegs,  spreads  it  in  a  thin  layer  and  attaches  it 
to  the  surface  at  which  the  nest  is  to  be  started.  Layer  after 
layer  of  fibre  is  added  in  this  way  until  the  nest  is  completed. 

The  enormous   structures  made  by 
^''^'-  4^^-     ^  the     "  white-faced' '     wasp,     Vespa 

maculata,  are  excellent  examples  of 
what  can  be  accomplished  by  num- 
bers and  persistence.  As  to  feed- 
ing habits,  these  social  wasps  are 
usually  predaceous,  but  they  are 
also  fond  of  sweets,  and  may  often 
be  found  on  flowers,  gathering 
White-faced  uasp,;v.Av «;««,/,./«.     ^^o^^y,    or   on    ripe    fruits,   sucking 

their  juices.  We  also  find  them 
occasionally  in  butcher-shops,  and  they  have  a  fondness  for 
chewing  into  raw  meat  and  lapping  the  blood.  They  feed  their 
larvae  honey  and  other  plant  juices,  and  also  the  masticated  frag- 
ments of  insects.  That  is  to  say,  they  prepare  the  animal  food 
by  first  chewing  into  a  pulp  before  feeding  it. 

Two  types  of  these  wasps  are  common  throughout  the  United 
States, — the  first  rather  slender,  with  a  spindle-shaped  abdomen, 
and  usually  a  more  or  less  red-brown  color,  often  marked  with 
yellow.  These  belong  to  the  genus  PoHstes,  and  they  build  their 
paper  combs  openly, — that  is,  without  any  covering,  and  sus- 
pended by  a  single,  short,  central  stalk.  The  colonies  rarely 
become  very  large,  but  they  are  very  numerous  in  most  parts  of 
the  country. 

The  true  "wasps,"  or  members  of  the  genus  Vespa,  have  the 
abdomen  cylindrical,  squarely  cut  off  where  it  joins  the  thorax, 
and  are  very  often  contrastingly  marked  with  white  or  yellow, 
occasionally  with  red  or  brown  on  a  black  ground.  These  are 
the  "hornets"  and  "yellow-jackets,"  and  their  colonies  some- 


THE    INSECT    WORLD.  407 

times  become  of  enormous  size,  many  hundreds  of  individuals 
being  found  in  a  single  nest  in  the  latter  part  of  the  season. 
Durability  is  not  looked  for  by  the  insects,  and  the  winter  storms 
and  snows  disintegrate  the  paper  structures,  so  that  in  spring  it 
is  rarely  possible  to  find  them,  however  abundant  they  may  have 
been  during  the  summer  previous. 

Wasps  are  beneficial,  as  a  whole,  since  they  feed  largely  upon 
other  insects  and  never  directly  upon  crops.     They  are  a  nui- 

FiG.  463, 


Nest  of  PoUstes  i^allicola. 

sance  sometimes  in  the  orchard,  where  they  are  apt  to  attack  all 
fruits  that  show  the  least  trace  of  injury  or  decay,  and  they  have 
been  accused,  as,  indeed,  have  the  bees  as  well,  of  actually  punct- 
uring juicy  specimens  to  get  at  the  liquid  contained  in  them. 
Some  of  the  species  are  undoubtedly  useful  in  pollenizing  fruit 
flowers,  but  there  are  none  of  pre-eminent  advantage  in  this  di- 
rection. 

The  last  family  in  the  order  contains  the  bees,  and  these,  as  in 
the  wasps,  may  be  either  social  or  solitary.  The  solitary  bees 
are  those  in  which  male  and  female  only  are  developed,  and  their 
habits  in  nest-building  resemble  in  many  cases  those  of  the 
wasps.  Thus,  we  have  species  that  build  in  the  ground,  those 
that  make  cells  in  the  pith  of  plants,  others  that  are  true  carpen- 
ters and  bore  tunnels  in  solid  wood,  and,  in  short,  we  may  find 
bee  homes  in  much  the  same  situation  that  we  find  wasp  domi- 
ciles.    Their  cells  may  be  distinguished,  however,  in  all  cases  by 


4o8  AN  ECONOMIC  ENTOMOLOGY. 

the  fact  that  they  are  stored  with  a  mixture  of  pollen  and  honey, 
or  honey  or  pollen  alone,  instead  of  with  insects,  and  it  is  this 
habit  of  collecting  pollen  that  makes  the  bees  so  highly  useful  to 
the  farmer,  by  their  incidentally  pollenizing  the  flowers  from 
which  the  material  is  gathered.  There  are  several  interesting 
structural  modifications  in  the  bees  to  facilitate  the  work  of  gath- 
ering both  pollen  and  honey,  and,  incidentally,  of  accomplishing 
pollination  to  the  best  advantage.  Thus,  the  clothing,  instead 
of  being  composed  of  simple  cylindrical  processes,  is  com- 
posed, in  large  part,  at  least,  of  bristly,  plumose  or  twisted 
hair, — that  is  to  say,  each  hair  is  furnished  with  Httle  spurs, 
or  long,  slender  branches,  making  it  resemble  a  plume  under 
the  microscope.  Or  it  may  be  twisted  like  a  screw,  or  fur- 
nished with  a  knob  at  the  tip.  The  result  is,  that  as  the  insects 
move  over  the  flowers,  the  pollen  grains  adhere  to  the  vestiture, 
and  this  also  accounts  for  the  fact,  probably  noticed  by  every  ob- 
servant fruit-grower,  that  bees  frequently  bury  themselves  com- 
pletely in  the  blossoms,  or  roll  over  every  part  of  them.  Such 
insects  are  after  pollen,  not  honey,  and  by  so  rolling  about  the 
pollen  grains  are  brought  into  contact  with  and  adhere  to  the 
surface  of  the  insect.  Incidentally,  also,  as  soon  as  the  bee  flies 
from  one  flower  to  another,  and  repeats  this  operation,  a  sufficient 
number  of  pollen  grains  from  the  first  flower  adhere  to  the  stigma 
of  the  second  and  poUenize  it  ;  while  in  flying  from  one  tree  to 
another,  cross-pollination  is  accomplished.  The  flowers  visited 
in  this  way  by  a  single  bee  are  very  numerous.  When  a  honey- 
bee becomes  more  or  less  covered  with  pollen,  it  cleans  itself  by 
means  of  specialized  structures  on  the  legs,  which  enable  it  to 
literally  comb  out  its  entire  body  covering.  The  masses  of  pol- 
len gathered  in  that  way  are  then  rolled  into  a  lump  and  fastened 
to  the  upper  side  of  the  posterior  tibia,  where  lateral  fringes  of 
long  hair  hold  it  in  place  and  actually  form  a  basket.  These 
combing  arrangements  are  situated  on  the  first  joint  of  the  hind 
tarsi,  which  is  broadened  for  that  purpose  in  the  social  bees,  and 
is  usually  much  longer  than  the  other  tarsal  segments.  Some 
bees  have  pollen  baskets  not  only  on  the  tibia,  but  on  the  femur 
and  coxa  as  well,  and  occasionally  the  whole  posterior  portion  of 
the  thorax  and  the  space  between  the  thorax  and  abdomen  is 
utilized  to  store  the  pollen  masses.     Sometimes  the  under  side  of 


Ik..   ^04. 


A  iilatc-  of  bees.-,/,  .\fr/is.\(>({,s  /uiiiacu/alus  .■  />,  Aintiriia  vunni :  c .  (.'irlioxvs  S-driitala  :  d, 
Haltctus  ligatus:  r,  Sytilnilomia  aliivriiliis;/,  Ostiiiu  i/is/ici.-g.  Andirua  riigrniic :  //,  Mrlis- 
sodrs  iiisiip/s:  i,  Mcsriuliilr  mciidica :  k.  Xriinglossii  /»niiiiia:  I,  Tachylcs  mandibularis ;  m. 
Mrfrachil,-  laliiiiaiius.     All  lallu-i  more  than  twice  tiatiiial  size. 


:^^gS^;^!^^';^^fkf<;x';v^4^ 


-    _     -t 4- ^ — * «— <3 — ^ «: ^ ^—^ ^ ,,--     jT     ijf 


T~T^C  ;  »-g^ 


409 


4IO 


AN  ECONOMIC  ENTOMOLOGY. 


the  abdomen  contains  the  pollen-gathering  structure, — that  is  to 
say,  the  segments  of  the  abdomen  are  furnished  with  brushes  of 
long,  twisted  or  knobbed  hair,  and  all  the  pollen  gathered  by  the 

Fig.  468. 


Fig.  469. 


Modifications  of  the  hind  legs  of  different  bees.— /I,  Apis:  a,  wax  cutter  and  outer 
view  of  leg;  b,  inner  aspect  of  wax  cutter  and  leg  ;  c,  compound  hairs  ;  d,  anterior  leg, 
showing  antenna!  scraper.  £,  Melipona  :  /,  peculiar  group  of  spines  at  apex  of  tibia; 
g,  inner  aspect  of  wax  cutters  and  first  joint  of  tarsus.  C,  Bomdus  :  h,  wax  cutter;  i, 
inner  view  of  same  and  first  joint  of  tarsus  ;  all  enlarged. 

insect  is  stored  among  it,  ready  for  transportation  to  the  nest. 
Pollen,  however,  forms  only  one  portion  of  the  food  of  the  larva, 
and  it  must  be  mixed  with  honey  to  form  "  bee  bread"  of  a  proper 

composition.  This  honey  is  also 
gathered  from  flowers,  and  the 
mouth  parts  are  modified  to  this 
especial  end. 

We  have  two  series  of  bees  dis- 
tinguished by  the  character  of  the 
mouth  parts, — the  short-tongued 
and  the  long-tongued, — both  of 
which  may  be  either  solitary  or 
social.  The  short-tongued  bees 
have  the  lower  lip  modified  into  a  bladder-like  structure,  more 
or  less  pointed  at  the  tip,  and  set  with  regular  rows  of  short  hair 
or  flattened  processes,  an  ideal  tongue  for  gathering  up  the  liquid 
nectar  and  bringing  it  into  the  mouth.  Many  of  these  bees  are 
diggers,  and  build  their  nests  in  the  ground,  usually  forming  a 
single  vertical  burrow  from  which  lateral  branches  diverge  into 


Abdomen    of   Megachile   fitted    for 
gathering  pollen. 


THE    INSECT    WORLD. 


411 


IG.    470. 


small  cells,  each  containing  a  supply  of  food  sufficient  for  a 
single  larva.  The  mother  bee  constructs  a  cell,  fills  it  with  a 
mixture  of  pollen  and  honey,  and 
lays  an  o^^^  in  it.  Then  she  closes 
up  the  chamber,  and  her  work  as 
to  this  particular  larva  is  com- 
pleted. When  the  q^^  hatches, 
the  larva  finds  a  food  supply  im- 
mediately at  hand  sufficient  to 
bring  it  to  maturity.  When  it  is 
fully  grown  it  changes  to  a  pupa, 
and  eventually  to  an  adult,  which 
then  makes  its  way  from  the  earth- 
en home  into  the  sunlight.  The 
mother  bee  having  completed  one 
cell,  at  once  begins  the  construc- 
tion of  another,  and  thus  the 
w^ork  is  continued  until  the  supply 
of  eggs  is  exhausted.  The  open 
face  of  sand-  or  clay-banks  is  a 
favorite  place  for  these  insects,  and 
sometimes  they  build  their  nests 
together  in  great  numbers. 

The  long-tongued  bees  are  so 
called  because  the  ligula  or  glossa 
is  extended  into  a  flexible  ribbon- 
like structure,  ringed  but  not  seg- 
mented, set  with  circles  of  long 
hair,  and  frequently  tipped  with  a 
little  button-like  structure.  This 
enables  the  insect  to  reach  the 
honey  in  deep  flowers  like  the 
clovers,  and  in  fact  there  are  only 
certain  bumble-bees  with  a  tongue 
long  enough  to  reach  the  nectaries 
of  the  red  clover  flowers  ;   hence 

they  are  entirely  dependent  upon  these  for  pollination.  Destroy 
the  bumble-bees,  and  no  red  clover-seed  can  be  obtained.  It  is  a 
suggestive  fact  that  in  many  localities  where  ruthless  war  is  waged 


vrv<^>^ 


Buiiowol  in  ii  ita  show  1111;  lcIIs  111 
...der  v^f  cc.j^l^t.v,.. ,  tl.e  f.rot  .a  c»,  U.e 
last  aty,  in  which  an  egg  has  just  been 

laid. 


412  AN  ECONOMIC  ENTOMOLOGY. 

against  bumble-bees,  it  is  becoming  increasingly  difficult  to  obtain 
clover-seed,  and  for  this  particular  purpose  those  insects  should 
be  carefully  cherished.  They  are  sometimes  a  nuisance  when  in 
the  course  of  mowing  or  reaping  a  nest  is  disturbed,  but  the 
slight  annoyance  then  caused  scarcely  warrants  the  complete  de- 
struction of  the  nest  which  so  uniformly  follows.  The  farmer 
who  destroys  every  nest  of  bumble-bees  on  his  land  destroys  a 
series  of  insects  than  which  none  are  more  useful  to  him,  particu- 
larly if  he  raises  fruit  or  has  any  desire  to  obtain  red  clover-seed. 
The  long-tongued  bees  may  be  either  social  or  solitary,  and 
there  is  no  superficial  character  known  to  me  by  which  the  solitary 
bees  can  be  readily  distinguished  from  the  social  forms,  except  by 
the  presence  of  the  wax-producing  organs  in  the  latter.  The 
habits  of  the  bees  differ  greatly:  some  are  cuckoos,  some  have  been 
supposed  to  be  parasitic,  while  the  majority  are  undoubtedly 
honest  workers  and  provide  decently  for  their  families.  Many  of 
them,  as  has  been  already  stated,  are  carpenters,  and  some  of  them 
are  tailors  or  upholsterers  as  well,— that  is  to  say,  after  having 
bored  out  the  wooden  tunnel  in  which  the  family  is  to  be  raised, 
the  cells  are  constructed  of  leaf  fragments.  Rose  leaves  or  those 
of  other  plants  of  the  family  RosacecB  are  frequently  noticed  with 
circular  or  semicircular  pieces  cut  from  the  edges.  This  is  done 
by  a  bee  of  this  tribe,  usually  a  Megachile,  and  these  little  frag- 
ments are  used  in  constructing  a  somewhat  thimble  shaped  cell. 
When  one  of  them  is  completed  it  is  filled  with  pollen  and  honey 
and  an  Qgg  is  laid  in  it  ;  then  another  is  built  on  top  of  it,  and  so 
on  until  the  burrow  is  completely  filled.  As  the  undermost 
specimen  matures  first,  it  bores  to  the  surface  through  a  hole  at 
the  end,  to  avoid  the  necessity  of  working  its  way  through  all  its 
younger  relatives  above  it.  The  largest  of  our  carpenters  is  the 
Xylocopa  virginica,  which  is  generally  mistaken  for  a  Bombiis, 
being  fully  as  large,  as  robust,  and  colored  yellow^  and  black, 
with  a  metallic  blue  reflection  on  the  abdomen  ;  but  the  head  is 
very  much  broader  than  in  any  bumble-bee,  and  equal  to  the 
width  of  the  thorax  itself  The  eyes  also  are  larger  and  white 
or  yellowish  in  color,  distinguishing  the  insect  at  once  from  true 
Bombus.  This  species  makes  galleries  half  an  inch  in  diameter 
in  the  solid  wood,  and  raises  a  considerable  family  in  the  course 
of  the  year.     The  partitions  between  the  cells  are  made  in  this 


Fig  471. 


Mouth  of  bumble-bee. — The  liexible  tongue  central,    flanked  by  the  long:  palpi;  the  lateral 

parts  are  the  maxillae. 


THE    IXSECT    WORLD. 


413 


case  of  little  chips  of  wood  cemented  together.     They  are  very 
common    and   sometimes  troublesome  where   they  make   their 


galleries  in  the  wood  of  piazzas  and  out-buildings  of  country 
houses.  Nothing  will  be  gained  by  giving  detailed  descriptions 
of  these  solitary  bees,  since  their  general  habits  are  practically 


414 


AN  ECONOMIC   ENTOMOLOGY. 


alike,  and  it  need  only  be  said  that  all  are  useful  and  none  are 
in  any  true  sense  of  the  word  injurious. 

The  social  bees  are  among  the  most  interesting  of  all  the 
insects,  yielding  only  to  the  ants  in  the  perfection  of  their  colo- 
nial organization.  The  domesticated  honey-bee.  Apis  mellijica, 
may  be  accepted  as  the  type  of  the  highest  development  in  this 
family.  Here  we  have  in  each  hive  a  queen,  or  fully  developed 
female,  who  is  often,  under  normal  conditions,  the  mother  of 
every  individual  contained  in  it.  She  does  not  labor,  is  carefully 
tended  by  workers  who  provide  for  all  her  wants,  and  her  only 
function  is  to  supply  a  sufficient  quantity  of  eggs  for  the  brood- 
cells.  The  comb  made  by  the  hive-bee  is  so  universally  known 
that  no  time  need  be  wasted  in  describing  it ;  nor  is  it  important 
to  say  just  how  the  wax  is  produced,  save  to  state  that  it  is 
excreted  by  special  glands  on  the  under  side  of  the  abdomen  of 
the  workers  in  plate-like  masses.  These  are  gathered  together, 
kneaded  by  the  jaws,  and  placed  in  position  on  the  comb.  These 
waxen  cells  are  used  either  as  cradles  for  the  young  or  for  storing 
the  honey  against  such  time  as  no  food  can  be  obtained  ;  for, 
unlike  the  bees  previously  spoken  of,  the  whole  colony  lives 
through  the  winter,  and  requires  a  certain  amount  of  food  to 
maintain  it  until  work  can  be  resumed  the  spring  following.  Of 
these  storing  habits  man  has  made  use  ;  but  there  are  a  number 
of  wild  species  belonging  to  other  genera  than  Apis  that  have 
similar  tendencies.  The  life  in  a  hive  proceeds  something  as 
follows  :  the  workers,  who  are  the  real  rulers,  determine  about 
how  many  young  should  be  raised  during  the  season,  and  build 
the  proper  number  of  brood-cells,  making  three  distinct  sizes. 
The  smaller  are  intended  for  workers,  which  here,  as  elsewhere 
in  the  Hyme7ioptera,  are  simply  undeveloped  females  ;  the 
larger  are  to  contain  males  or  drones  ;  while  a  very  few,  irregular, 
somewhat  flask-shaped  cells  are  plastered  at  the  sides  of  the 
combs,  and  are  intended  for  new  queens  or  perfect  females.  The 
queen  lays  an  o^g^  in  each  of  the  brood-cells,  and  never  makes  a 
mistake  in  its  character.  She  lays  drone  eggs  in  the  drone  cells, 
and  drones  only  are  produced  from  them.  In  the  worker  cells 
workers  only  are  matured,  while  in  the  queen  cells  fully  developed 
females  are  raised.  It  is  interesting  to  note  that  the  insects  have 
the  matter  of  sex  under  perfect  control,  and  it  is  believed  that 


TIIK    INSECT    WORLD. 


415 


the  eggs  producing  drones  are  not  fertilized  :  this  matter  being 
under  direct  volition  of  the  female.  The  larvce  are  carefully  fed 
by  the  workers,  and  each  variety  receives  a  different  kind  of 
"bread,"  especially  prepared  for  it.  The  workers  are  fed  on 
what  seems  to  be  best  adapted  for  them  ;  the  drones  receive 
another  kind  ;  while  the  future  queens  live  on  a  specially  prepared 
product,  or  "  royal  food,"  supposed  to  be  much  richer  in  nitroge- 
nous materials.  When  the  larvae  are  full-grown,  the  cells  are 
capped  and  the  pupae  form  in^^ide  of  them.  In  due  time  the 
adults  issue,  either  drones  or  workers.  In  the  former  case  they 
idle  about,  doing  nothing,  except  to  find  food  for  themselves.  In 
the  latter  case  they  at  once  assume  their  full  share  of  the  duties 
of  the  hive,  gathering  honey  or  pollen,  or  attending  to  whatever 
else  is  to  be  done.  Of  course,  by  this  continuous  increase  the 
hive  soon  becomes  overcrowded,  and  then  the  question  arises,  Is 
the  colony  in  condition  to  stand  a  swarm  ?  If  the  store  combs 
are  tolerably  well  supplied,  and  everything  is  running  smoothly, 
the  question  is  decided  in  the  affirmative,  and  arrangements  are 
made  to  have  a  portion  of  the  inhabitants  leave  it.  Meanwhile 
the  queen  larvae  have  continued  to  develop,  and  are  now  ready 
to  assume  the  adult  form.  When  this  period  arrives,  the  ruler 
of  the  hive  becomes  uneasy,  and  does  her  best  to  get  at  the 
queen  cells  to  kill  her  maturing  rivals.  If  the  workers  have 
decided  that  they  need  a  s\varm,  she  is  kept  from  doing  mischief 
and  they  simply  block  her  way.  When  the  new  females  have 
issued,  every  effort  is  made  to  prevent  a  meeting  between  the 
young  and  old,  or  even  between  the  young  queens,  if  there  is 
more  than  one.  With  the  new  queen  or  queens  fully  developed, 
and  a  larger  number  of  workers  than  can  be  readily  accommo- 
dated, the  members  of  the  hive  become  uneasy,  cease  work,  and, 
from  the  noise,  appear  to  be  holding  a  caucus,  which  finally 
results  in  a  considerable  proportion  leaving  the  hive  under  the 
leadership  of  either  the  old  or  one  of  the  new  queens.  This  is  a 
"  swarm,"  and  it  flies  a  longer  or  shorter  distance  before  it  settles 
in  a  solid  mass,  usually  surrounding  the  queen.  If  the  swarm 
is  not  hived  at  once,  the  bees  sooner  or  later  find  a  hollow  tree 
or  other  cavity,  where  they  start  a  colony  ;  but  if  the  insects  are 
under  the  care  of  a  proper  keeper,  the  indications  are  noted,  and 
.when  the  swarm  leaves  the  hive  it  is  induced  to  alight  near  by, 


4i6  ^^  ECONOMIC   ENTOMOLOGY. 

either  through  a  jet  or  spray  of  water  directed  upon  it,  or  by- 
beating  tin  pans  or  making  some  other  noise.  When  the  swarm 
has  settled,  the  bees  can  be  shaken  into  a  receptacle,  and  if  the 
queen  is  contained  in  the  mass,  as  she  usually  is,  they  make 
themselves  at  home  readily  in  any  hive  to  which  they  may  be 
transferred,  especially  if  it  contains  a  small  supply  of  food  or  a 
piece  of  comb,  full  or  empty.  Work  is  then  started  at  once,  and 
the  colony  is  soon  in  full  swing.  From  a  sound  colony  there  may 
be  several  swarms  in  the  course  of  a  season  ;  but  if  times  have  been 
bad  and  the  bees  have  not  increased  sufficiently  to  warrant  it, 
there  is  no  swarming,  and  nothing  is  placed  in  the  way  of  the  old 
queen  to  prevent  her  from  killing  her  immature  rivals,  unless, 
indeed,  the  bees  decide  that  she  is  worn  out  and  incapable  of 
supplying  a  sufficient  quantity  of  eggs,  in  which  case  they  permit 
one  or  more  young  queens  to  come  to  maturity  and  let  them 
fight  it  out.  The  victress  remains  queen  of  the  hive,  and  if  it  is 
the  young  female,  the  inhabitants  transfer  their  allegiance  to  her 
without  question,  and  serve  her  as  faithfully  as  they  did  their 
original  ruler.  If  by  any  chance  the  bees  lose  their  queen,  and 
have  no  royal  larvae,  they  take  worker  eggs  or  very  young 
larvae,  and  by  proper  care  and  feeding  make  queens  of  them  : 
royalty  in  this  case  being  a  mere  matter  of  diet. 

As  to  the  practical  part  of  bee-keeping,  and  the  details  neces- 
sary, there  are  many  books  especially  written  to  give  that  infor- 
mation, and  it  forms  no  part  of  the  purpose  of  the  present  treatise. 
The  object  here  has  been  to  give  merely  a  sufficient  insight  into 
the  working  of  the  hive  to  indicate  the  use  that  is  made  of  the 
pollen  and  its  importance  in  the  economy  of  bee  life.  It  is  the 
necessity  of  having  food  for  the  larvae  that  keeps  the  insects 
constantly  at  work  and  makes  them  so  effective  as  poUenizers. 
Visiting,  as  they  must  do,  a  great  number  of  flowers  to  obtain 
sufficient  pollen  for  a  load,  they  call  at  many  trees,  often  far 
apart  and  of  different  varieties,  securing  the  cross-pollination  so 
necessary  to  many  plants.  They  usually  visit  one  kind  of  flower 
only,  and  I  have  tested  several  specimens  by  microscopic  investi- 
gation, finding  always  one  form  of  pollen  only. 

Bumble-bees  have  been  already  mentioned,  and  resemble  in 
their  economy  somewhat  the  hive-bee,  save  that  here,  as  in  the 
wasps,  the  colony,  excepting  only  the  fully  developed  females, 


THE    INSECT   WORLD. 


417 


dies  each  year.  We  see  early  in  the  spring,  when  the  fruit- 
trees  are  in  bloom,  many  specimens  droning  about  on  the 
flowers,  but  often  also  along  road -sides,  especially  where  there  is 
a  declivity  ;  or  in  fields  where  there  are  a  few  rocks,  or  where 
there  are  holes  in  the  ground.  There  we  often  notice  an  indi- 
vidual buzzing  over  one  spot  for  several  minutes  at  a  time, 
apparently  subjecting  it  to  the  closest  kind  of  examination.  This 
is  indeed  what  the  insect  is  doing  :  she  is  seeking  a  place  to 
start  a  home.  This  she  finds  in  an  abandoned  mouse-hole,  or 
other  cavity  in  the  ground,  and  here  begins  her  nest,  lining  it 
with  moss,  with  fragments  of  leaves  or  grass,  or  with  whatever 
may  be  most  convenient.  Then  she  gathers  a  mass  of  pollen, 
upon  which  a  number  of  eggs  are  laid.  No  comb  is  built ;  but  the 
larvae,  when  they  hatch,  burrow  into  the  pollen  mass,  to  which  the 
mother  adds  constantly  as  necessity  requires.  When  full-grown 
each  forms  a  smooth  cavity,  which  it  lines  with  a  silken  cocoon 
and  changes  to  a  pupa.  The  cocoon  is  strengthened  from  the 
outside  by  the  mother,  with  wax,  and  in  due  time  we  have  a  little 
brood  of  worker  ' '  bumbles' '  resembling  their  parent  in  all  except 
size  and  the  incomplete  sexual  development.  Not  until  after  mid- 
summer does  the  queen,  reinforced  by  the  workers  which  she  has 
raised,  lay  eggs  that  produce  males  and  females,  and  these  are  fed 
upon  food  gathered  by  the  workers.  The  old  female  dies  when  the 
new  brood  of  sexually  complete  individuals  has  hatched.  The 
latter  mate,  and  the  workers  and  males  also  die  on  the  approach  of 
cold  weather,  leaving  only  the  now  impregnated  females  to  survive. 
Taken  altogether,  the  order  Hymenoptera  contains  insects  that 
are  decidedly  beneficial  to  the  farmer.  The  first  series  only,  to 
which  the  "saw-flies"  and  the  "borers"  belong,  are  injurious, 
and  these  may  always  be  recognized  by  the  fact  that  the  abdomen 
joins  the  thorax  by  its  whole  width,  instead  of  being  fastened 
simply  by  a  stalk  or  petiole.  Of  course,  the  ants  are  sometimes 
troublesome  and  indirectly  injurious,  but,  as  a  whole,  the  species 
are  so  overwhelmingly  beneficial  that  the  order  deserves  to  be 
encouraged  in  every  way  possible.  Bees,  wasps,  and  hornets 
are  particularly  desirable  inhabitants  of  a  locality,  and  in  a  quiet 
way  do  much  to  destroy  injurious  insects, — as  much,  perhaps,  as 
the  parasites  which  also  belong  to  the  order  ;  while  the  bees  of  all 
kinds  are  simply  indispensable  to  the  fruit-grower  as  poUenizers. 

27 


PART    III. 

INSECTICIDES,  PREVENTIVES,  AND 
MACHINERY. 


CHAPTER    I. 

PREDACEOUS    INSECTS,    PARASITES,    AND    FUNGOUS    DISEASES. 

It  has  appeared  throughout  this  book  that,  while  we  have  a 
great  many  insects  that  are  feeders  upon  vegetation,  there  are 
also  a  great  number  that  are  predaceous  upon  the  herbivorous 
forms,  and  yet  many  others  that  are  parasites,  living  upon  or 
within  others  of  the  same  class.  It  is  a  tempting  proposition 
that  we  may,  perhaps,  be  able  to  array  the  forces  of  nature 
against  each  other  ;  that  we  may  keep  predaceous  forms,  and  set 
them  free  at  the  proper  season  to  feed  upon  those  injurious  to 
farm  crops.  I  say  it  is  a  tempting  proposition,  and  it  looks 
feasible,  but  that  it  should  be  successful  involves  a  great  deal 
more  than  is  apparent  at  first  glance.  In  the  course  of  the  ages 
through  which  this  world  has  existed  there  has  been  gradually 
established,  by  the  influence  of  surroundings,  a  certain  ratio  be- 
tween all  existing  life,  vegetable  and  animal.  There  is  a  struggle 
among  the  plants  themselves  as  to  which  shall  keep  the  ground, 
and  upon  the  plants  feed  animals,  including  insects,  which  form 
a  factor  in  determining  the  relative  abundance  of  the  different 
species.  With  the  development  of  the  plants  their  enemies  also 
have  developed,  and  always  in  proportion  to  the  amount  of  injury 
that  the  plant  can  stand.  That  this  must  be  so  is  evidenced  by 
the  fact  that  the  plants  exist  at  all.  One  of  nature's  ways  of  pre- 
venting the  plant-feeding  insects — for  we  will  confine  our  re- 
marks to  insects  from  this  point  on — from  obtaining  control  of 
and  exterminating  the  plants  is  to  provide  enemies  of  various 
418 


IXSECTICIDES,    PREVENTIVES,   AM)    MACHINERY.      419 

kinds  for  them.     These  enemies  in  turn  must  be  checked,  that 
they  may  not  exterminate  the  species  they  themselves  feed  upon. 
Thus  there  has  been  established,  gradually  and    naturally,   an 
elaborate  system   of  checks   and   counterchecks,  by  means   of 
which  a  certain  proportion  is  maintained  year  in  and  year  out 
between  i)redaceous,  parasitic,  and  plant  feeding  insects.     Under 
perfectly  natural  conditions  this  ratio  does  not  change  much  from 
year  to  year,  and  there  is  no  preference  on  the  part  of  nature  for 
one  class  as  against  any  other.     Any  interference  with  this  estab- 
lished course  is  almost  certain  to  be  disadvantageous  in   some 
directions,  and  man,  in  his  dealings  with  natural  conditions,  has 
persistently  created  for  himself  a  series  of  troubles  arising  from 
his  own  acts.     By  planting  large  areas  of  one  crop,  he  has  fa- 
vored the  increase  of  the  insects  feeding  upon  that  crop.     By  cul- 
tivating the  land,  keeping  it  cleared  of  rubbish,  stones,  sticks, 
and  the  like,  he  has  destroyed  the  shelter  needed  by  predaceous 
insects,  and  the  result  is  that  he  has  in  two  ways  given  those  in- 
sects, which  he  now  calls  injurious,  an  advantage.     The  conse- 
quences, of  course,  are  against  him  ;  and  so  long  as  these  condi- 
tions continue,  favoring  one  class  at  the  expense  of  another,  man 
must  suffer,  unless  he  himself  fulfils  the  functions  previously  as- 
signed to  the  predaceous  forms.     True  parasites  have  not  been 
so  much   influenced  by  his  actions,   and   the  species,   perhaps, 
suffer  as  much  from   them   as  they  ever  did  ;    but  the  natural 
checks   in   operation   against   the   parasites  also   continue,  and 
while,  perhaps,  they  have   increased  somewhat  in  number,  they 
have  not  been  able  to  make  up  for  the  loss  of  the  predaceous  in- 
sects.    Furthermore,   the  feeders  upon  vegetation  suffered  also 
from  the  attacks  of  insectivorous  animals,  like  toads,  frogs,  and 
snakes  among  the  reptiles,  and  many  small  animals  and  birds, 
which  now  also  find  life  insupportable  among  the  artificial  condi- 
tions.    The  result  is  that  there  has  been  an  actual  increase  in  the 
number  of  specimens  of  injurious  insects,  and  their  parasites  bear 
somewhat  less  than  their  original  ratio  to  them, — that  is,  each 
year  a  certain  proportion  or  percentage  of  a  brood  is  destroyed 
by  its  parasites,  and  this  percentage  it  is  beyond  our  present 
power  to  change  to  our  advantage.     In  other  words,  the  farmer 
cannot,   except   in   isolated   instances,    count   upon  parasites   or 
natural  enemies  of  any  kind  to  keep   down    injurious   insects. 


420  ^^   ECONOMIC  ENTOMOLOGY. 

Even  though  in  each  year  a  certain  species  may  be,  in  the  long 
run,  controlled  by  its  parasite,  this  does  not  necessarily  help  the 
farmer.     Let  us  take,  for  instance,  the  cut-worms  that   are   so 
abundant  each  year.     If  we  gather  from  an  infested  field  two  or 
three  hundred  specimens,  we  find  that  anywhere  from  fifty  to 
seventy-five  per  cent,  of  them  are  parasitized.     This  looks  like  a 
huge  destruction  ;  but  when  we  consider  that  the  parasites  do 
not   as  a  rule,  affect  the  larvae  until  they  have  done  all  their 
feeding,  what  benefit  has  the  farmer  derived?     What  difference 
does  it  make  whether  the  cut-worm  that  destroys  his  plants  is 
parasitized  or  not?     At  the  end  of  the  season  we  may  note  that 
twenty-five  per  cent,  only  of  the  cut-worms  develop  into  moths  : 
half  of  those  may  be  males,  and  the  remainder  are  females  which 
will  each  lay  anywhere  from  three  to  five  hundred  and  some- 
times more  than  one  thousand  eggs  ;  amply  sufiicient  to  pro- 
duce in  the  next  brood  fully  as  many  caterpillars  as  existed  in 
the  beginning  !     Let  us  further  take  the  case  of  the  cranberry 
Teras\s  an  illustration.     The  first  brood,  early  in  the  season, 
has  scarcely  any  parasites  ;  the  second  brood,  in  mid-summer, 
is  parasitized  to  the  extent  of  nearly  fifty  per  cent.  ;  while  from 
the  third  brood,  in  the  fall,  we  get  fully  seventy-five  per  cent, 
of  parasites  to  twenty-five  per  cent,  of  moths.      Yet,   notwith- 
standing this  enormous  increase  of  the  parasites  in  the  course 
of  the  season,  some  combination  of  circumstances  destroys  so 
many  of  them  during  the  winter  that  in  the  spring  following 
the  first  brood  is  again  almost  free  from  attack  ;    and  thus  it 
goes,  year  after  year.     The  action  of  the  parasite  is  only  to  keep 
its  host  within  a  certain  fairly  well  defined  limit,  and  if  that 
limit  is  at  a  point  where  the  host  becomes  injurious  to  the  farmer, 
he  must  himself  take  a  hand  in   its  destruction  to  derive  any 
benefit.     I  do  not  mean,  in  anything  I  say  here,  to  lessen  the 
claims  of  parasitic  and  predaceous  insects  to  our  consideration. 
They  have  an  extremely  important  function  in  nature,  and  with- 
out them  there  would  be  no  possibility  of  an  existing  vegetation. 
But,  on  the  other  hand,  it  is  just  as  certain  that  unless  there  was 
some  check  imposed  upon  the  mukiplication  of  parasites,  etc., 
they  would  in  a  short  time  destroy  the  insects  that  they  feed 
upon,  and  the  destruction  of  their  host  would,  logically,  carry 
with  it  their  own  destruction.     Nature  never  works  in  that  way  : 


INSECTICIDES,    PREVENTIVES,    AND   MACHINERY.      421 

lier  effort  is  always  to  give  all  her  creatures  an  equal  chance  to 
exist. 

Man  has  I'urther  disturbed  the  natural  conditions  by  introducing 
into  new  countries  insects  that  have  become  ada[)ted  to  the  sur- 
roundings in  others.  Sometimes  an  insect  so  introduced  does 
not  find  the  new  circumstances  to  its  liking  ;  but,  on  the  other 
hand,  it  may  find  them  very  much  better  than  those  under  which 
it  was  originally  developed.  In  such  cases  we  get  a  multiplica- 
tion out  of  all  proportion  to  the  normal  habit  of  the  species,  and 
there  may  be  such  a  thing  as  the  destruction  of  the  plants  that 
they  feed  upon.  Let  us  take,  for  instance,  the  elm-leaf  beetle, 
introduced  into  this  country  many  years  ago,  and  apparently 
without  natural  enemies  suitable  for  its  control.  The  circum- 
stances which  it  finds  here  are  so  much  to  its  liking  that,  if 
allowed  to  increase  unchecked  by  the  efforts  of  man,  it  may  in 
the  course  of  time  destroy  all  the  European  elms  in  the  regions 
infested  by  it  ! 

The  whole  object  is  to  show  that,  since  man  has  introduced 
artificial  conditions,  he  must  bear  the  burden  of  the  change 
caused  by  them  ;  and  if  this  means  that  there  are  certain  injurious 
insects  feeding  upon  the  plants  he  wishes  to  grow  for  his  own 
benefit,  he  must  replace  by  his  own  efforts  those  natural  checks 
which  he  has  removed  by  the  artificial  conditions  introduced. 
Those  efforts  on  his  part  consist  in  the  adoption  of  measures  to 
prevent  increase,  or  to  destroy  the  injurious  insects  by  means 
of  poisons  or  otherwise,  and  this  subject  will  be  considered  in 
another  chapter. 

A  fascinating  theory  in  connection  with  this  subject  is  the  pos- 
sibility of  importing  parasites  or  predaceous  forms  from  other 
countries  for  the  destruction  of  pests  here.  This  leaves  out  of 
consideration  the  fact  that  it  would  require  a  readjustment  ol 
matters  to  induce  foreign  parasites  to  feed  upon  American  insects, 
and  it  has  never  been  proved  that  such  a  .thing  is  possible  within 
a  reasonable  period  of  time.  The  case  of  the  Australian  Vedalia, 
imported  to  prey  upon  the  fluted  scale,  Icerya  purchasi,  is  fre- 
quently cited  as  an  example  of  what  can  be  done,  but  always 
without  considering  the  fact  that  we  had  an  imported  insect  to 
deal  with  in  the  first  place,  which  increased  abnormally  in  our 
country  because  of  the  fact  that  its  enemies  were  not  brought 


422 


AN  ECONOMIC  ENTOMOLOGY. 


in  with  it.  When  this  Australian  insect  enemy  was  introduced, 
it  found  nothing  that  it  recognized  except  the  Icerya,  and,  in 
consequence,  devoted  itself  entirely  to  that  species,  totally  sup- 
pressing it  in  a  short  time.  All  that  was  done  here  was  to  re- 
store the  balance  of  nature,  because  the  scale  insect  is  a  tolerably 
rare  species  in  Australia,  owing  to  the  number  of  its  enemies. 
Nothing  can  be  argued  from  this  case  as  to  the  possibility  of  in- 
troducing foreign  species  to  control  strictly  American  pests  with 
which  they  are  not  acquainted.  An  effort  was  made  in  this 
direction  in  Virginia,  the  object  being  to  import  European  enemies 
of  bark-borers  to  check  the  invasion  which  seemed  to  threaten 
the  forests  of  that  State.  The  utmost  that  can  be  said  for  the 
experiment  is  that  the  imported  insects  have  not  quite  died  out, 
and  that  occasionally  one  is  seen  out  of  many  hundreds  brought 
in.  But,  on  the  other  hand,  the  invasion  which  they  were  im- 
ported to  check  has  been  disposed  of  by  nature  herself,  an 
unusually  severe  winter  destroying  the  pests  so  completely  that, 
instead  of  being  abnormally  abundant,  they  have  become  almost 
rarities.  We  can  frequently  do  good  where  we  have  imported 
insects,  or  insects  occurring  also  in  other  countries,  by  finding 
and  introducing  their  parasites  ;  but  it  seems  rather  an  Utopian 
scheme  to  train  predaceous  insects  of  other  countries  to  feed  upon 
our  native  species  with  which  they  are  not  acquainted. 

The  subject  of  fungous  or  contagious  diseases  of  insects  is  an 
interesting  one,  but  which  must  be  dismissed  here  with  a  brief 
reference  only.  We  know  that  insects  often  suffer  from  disease, 
and  that  epidemics  sometimes  occur  among  them,  destroying 
myriads.  Some  of  these  diseases  have  been  studied,  and  elab- 
orate attempts  have  been  made,  chiefly  in  Kansas  and  Illinois, 
to  make  use  of  them  practically.  The  chinch-bug  has  been  the 
insect  most  experimented  upon  ;  and  while  it  has  been  demon- 
strated that  it  is  possible  to  cultivate  the  disease  and  to  infect  pre- 
viously healthy  bugs  with  it,  it  has  also  developed  that  the 
disease  demands  certain  definite  conditions  of  climate  and 
atmosphere  for  its  own  propagation.  Thus,  dry,  warm  weather 
is  unfavorable  for  the  growth  of  the  disease,  while  it  favors  the 
multiplication  of  the  bugs  ;  but  moist  or  wet  weather,  which  re- 
tards development  in  the  bugs,  favors  the  disease.  Until  we  can 
control  climatic  conditions,   or  otherwise  secure  the  intelligent 


INSECTICIDES,    PREVENTIVES,   AND   MACHINERY.      423 

co-operation  of  the  weather,  our  results  are  Hkely  to  be  uncertain. 
Nevertheless,  there  may  be  great  possibilities  in  this  direction, 
and  in  the  minute  organisms  requiring  a  powerful  microscope  to 
make  them  even  visible  we  may  yet  find  our  most  effective  help 
in  checking-  destruction  by  insects. 


CHAPTER    II. 


FARM  PRACTICE  TO  PREVENT  INSECT  ATTACK, 

Throughout  this  work  reference  has  been  frequently  made 
to  methods  of  ordinary  farm  practice  for  preventing  insect  attack. 
It  is  desirable  to  look  a  little  closely  into  this  subject,  and  to 
detail  somewhat  the  methods  that  may  be  resorted  to  with  good 
effect.  Prevention  is  always  better  than  cure,  and  very  frequently 
serious  injury  may  be  averted  by  doing  ordinary  farm  work  at 
just  the  right  time,  or  in  exercising  care  in  the  selection  of  fer- 
tilizers or  in  the  rotation  of  crops. 

Far  above  everything  else  is  cleanliness  on  the  farm,  and  this 
term  is  to  be  construed  as  strictly  as  possible.  Cleanliness  means 
clean "  culture  ;  the  destruction  of  weeds  ;  the  removal  of  crop 
remnants  as  soon  as  the  crop  is  done  ;  picking  up  and  destroy- 
ing dropped  fruit  in  orchards  ;  removing,  burning  up,  or  other- 
wise destroying  all  rubbish  that  cumbers  the  ground  in  winter  ; 
keeping  buildings  painted  or  whitewashed  in  good  shape.  Allow 
no  rubbish,  weeds,  or  shrubbery  to  grow  among  the  fences,  and 
in  all  other  respects  leave  the  farm  as  nearly  bare  as  possible 
of  everything  save  what  strictly  belongs  there.  The  object  of  all 
this  is  to  do  away  with  possible  hiding-places  for  insects  during 
the  winter,  and  to  prevent  their  reaching  maturity  during  the 
summer.  A  large  proportion  of  insects  live  through  the  winter 
in  the  adult  stage,  or  in  the  partly  grown  condition,  and  a  great 
many  of  them  hide  under  rubbish.  Sometimes  they  get  just  a 
short  distance  below  the  surface  of  the  ground  among  the  roots  ; 
sometimes  they  crawl  into  crevices  of  fences,  of  logs,  or  of  boards, 
— wherever,  in  fact,  there  is  the  least  opening  for  them  to  get 


424 


A^V   ECO.YOMIC  ENTOMOLOGY. 


into.  A  tree  with  rough  bark,  covered  with  moss,  Hcheus  or 
other  unnecessary  growth,  often  harbors  hundreds  of  specimens, 
and  one  object  of  the  farmer  should  be  to  destroy  all  hiding- 
places  that  may  be  of  service  to  the  insects  for  winter-quarters. 
Therefore,  if  possible,  all  fences  should  be  whitewashed,  as  well 
as  all  out-buildings.  Insects  do  not  like  lime,  and  where  a  dozen 
specimens  may  be  found  on  a  plain  board  fence,  scarcely  one 
will  venture  on  one  that  is  limed.  This  kind  of  campaign  is 
especially  effective  against  certain  forms  of  plant-bugs,  a  large 
proportion  of  which  live  through  the  winter  in  the  half-grown  or 
adult  condition.  Offer  them  a  bare  soil  wherever  that  is  agricul- 
turally feasible,  and  at  all  events  never  give  them  the  opportunity 
of  hibernating  in  a  weedy  field — one  that  has  been  allowed  to 
grow  up  after  harvest  with  the  idea  that  it  is  to  be  turned  under 
in  the  spring.     Such  fields  are  veritable  nurseries  for  insect  pests. 

It  frequently  happens  that  a  farmer  is  through  with  a  crop 
before  the  plants  stop  growing,  and  occasionally  they  remain  in 
the  field  weeks  after  they  have  ceased  to  be  of  any  practical  use. 
During  all  this  time  the  insects  peculiar  to  that  crop  are  multi- 
plying, coming  to  maturity  undisturbed,  and  providing  for  their 
increase  during  the  ensuing  year.  For  instance,  with  cabbages  : 
if,  after  the  heads  are  taken  out,  the  butts  and  outer  leaves  are  left 
in  the  ground,  the  cabbage-lice  will  there  increase  and  prepare 
for  the  winter.  If  the  butts  are  taken  out  and  fed  up,  or  destroyed 
in  any  other  satisfactory  manner,  it  will  put  an  immediate  stop 
to  their  development  ;  and  if  the  practice  is  continued  systemati- 
cally, and  cruciferous  weeds  are  also  kept  down  on  the  farm, 
cabbage-lice  will  soon  become  so  reduced  in  number  as  to  be 
practically  harmless.  So,  from  melon  vines  only  a  portion  of 
the  crop  is  often  gathered,  and  they  are  then  left  to  grow  and 
decay  naturally  upon  the  ground.  The  vines  may  be  infested  by 
borers,  or  they  may  harbor  squash-bugs,  or  melon-lice,  or  a 
number  of  other  pests.  By  removing  and  destroying  as  soon  as 
there  is  no  further  use  for  them,  a  period  is  at  once  put  to  the 
increase  of  these  insects.  They  will  be  compelled  to  look  else- 
where for  food  or  will  starve  to  death. 

In  corn-fields,  leaving  the  roots  and  stumps  in  the  ground 
throughout  the  winter  offers  a  premium  for  the  increase  of  insects 
that  depredate  upon  this  crop.     Such  pests  as  "corn-worms" 


INSECTICIDES,    PREVENTIVES,   AND    MACHINERV.      425 

can  be  easily  kept  in  check  by  fall  ploughing  and  burning  the 
butts  and  roots,  and  a  good  effect  will  also  be  produced  as  against 
the  corn-root-louse  and  similar  pests.  Instances  might  easily  be 
multiplied  without  adding  to  the  force  of  the  suggestion  that  the 
ground  should  be  kept  as  free  as  possible  from  all  growth  that 
might  afford  lodgement  or  shelter  for  insects. 

Another  important  operation  which  can  be  made  use  of  is 
ploughing  at  the  proper  time,  and,  among  other  things,  fall 
ploughing,  whenever  possible,  is  to  be  recommended,  especially 
of  sod  land.  Many  different  kinds  of  insects  live  in  sod,  among 
them  cut-worms  and  wire-worms,  both  well-known  and  important 
pests.  A  great  deal  can  be  done  in  the  direction  of  destroying 
these  creatures  by  ploughing  the  land  late  in  fall.  Under  the 
proper  headings  will  be  found  the  reasons  why  such  an  operation 
proves  beneficial  in  special  cases  ;  but  in  general  we  can  say  that, 
by  disturbing  the  land  after  the  insects  have  prepared  for  their 
winter  rest,  they  are  exposed  to  their  natural  enemies  when  more 
helpless  than  usual.  A  great  many  are  then  in  the  pupa  state, 
absolutely  unable  to  help  themselves,  and  breaking  their  cells  at 
that  time  means  death  to  them.  A  very  large  percentage  of 
reduction  in  the  number  of  injurious  insects  can  be  effected  by 
this  practice  alone.  I  am  aware  that  fall  ploughing  is  inadvisable 
on  some  kinds  of  land,  but  it  is  directly  beneficial  on  others.  It 
is  a  measure  that  must  be  used  with  judgment,  and  each  farmer 
should  know  enough  about  his  own  land  to  decide  whether  or  not 
fall  ploughing  is  advisable.  I  distinctly  recommend  it  wherever 
it  is  possible.  As  a  rule,  where  the  ground  is  to  remain  bare, 
the  ploughing  should  be  done  as  late  in  the  season  as  possible, 
that  the  insects  may  not  be  able  to  re-establish  themselves  ;  for 
instance,  when  the  corn-root-louse  is  the  object  of  the  attack, 
early  ploughing  allows  the  ants  that  shelter  them  to  construct 
new  galleries  and  gather  in  their  belongings  to  safe  shelter,  while 
very  late  ploughing  makes  it  impossible  for  the  ants  to  work,  so 
that  they  and  the  lice  both  perish  :  the  latter  almost  certainly^ 
The  date  of  ploughing,  other  than  in  fall,  is  sometimes  important  ; 
thus,  against  the  root  web- worms  in  fields  after  grass,  if  the  sod 
is  turned  very  early,  before  the  moths  have  appeared  and  laid 
their  eggs,  the  crop  remains  free.  If  delayed  until  the  sod  has 
become  stocked  with  eggs,  the  corn  is  almost  certain  to  suffer. 


426  AN  ECONOMIC  ENTOMOLOGY. 

Sometimes,  where  land  cannot  safely  be  left  bare  during  the 
winter,  it  may  be  ploughed  earlier,  and  some  catch  crop,  simply 
to  cover  the  surface,  can  be  put  in,  and  it  matters  very  little  what 
this  is.  It  may  be  crimson  clover,  rye,  wheat, — anything,  in 
fact,  to  get  a  covering,  provided  it  is  something  radically  different 
from  what  was  on  the  ground  before  the  ploughing  was  done. 
Corn-fields  should  be  treated  in  this  way  after  the  crop  has  been 
harvested,  if  late  ploughing  is  undesirable,  for  it  is  always  a  mis- 
take to  leave  them  unturned  until  the  spring  following.  It  is 
a  good  plan,  just  as  soon  as  one  crop  is  off,  to  put  in  some- 
thing else,  which,  as  already  suggested,  should  be  quite  different 
in  general  character  ;  and  this  brings  up  the  question  of  rotation. 
It  is  impossible  to  make  any  generally  applicable  statements  on 
this  subject.  No  two  regions  of  our  country  are  entirely  alike  in 
their  practice,  in  the  crops  raised,  or  in  the  rotation  adopted  ; 
but  so  far  as  possible  a  rotation  should  be  selected  which  will 
keep  the  ground  covered  all  the  time,  the  crops  that  follow  each 
other  being  unlike  in  their  natural  family, — that  is,  grass  should 
not  follow  wheat  or  rye,  if  it  can  be  avoided  ;  nor  should  potatoes 
be  followed  by  egg-plants  or  tomatoes  ;  or  cabbages  by  mus- 
tard or  radishes  ;  but  in  all  instances  crops  as  diverse  as  may  be 
should  follow  each  other,  and  as  rapidly  as  possible.  Where 
wire-worms  are  the  chief  sinners,  crimson  clover  may  sometimes 
be  usefully  employed.  Plant  this  in  fall,  and  in  spring  it  will  be 
in  excellent  condition  to  attract  the  adults  to  lay  eggs.  Turn  it 
under  late  in  May  or  early  in  June,  after  cutting  for  hay  or  as  a 
green  manure,  and  plant  any  suitable  crop.  The  very  young 
larvae  will  be  incapable  of  doing  injury,  and  will  fail  to  maintain 
themselves  under  the  new  conditions.  It  must  be  remembered, 
however,  that  this  practice  will  favor  cut-worm  increase,  and 
measures  must  be  held  in  readiness  for  these  when  the  planted 
crop  makes  its  appearance. 

Another  good  plan  is  to  have  a  considerable  number  of 
chickens,  and  to  train  them  to  follow  the  plough.  This  can  be 
very  easily  done,  and  after  a  few  are  once  trained,  they  will  in 
turn  teach  the  entire  flock,  while  the  young  learn  readily  from 
the  older.  Chickens  following  a  plough  will  pick  up  almost 
every  insect  that  is  turned  up,  be  it  in  the  larval,  pupal,  or  adult 
condition,  and  they  are  especially  effective  in  fields  infested  by 


INSECTICIDES,    PREVENTIVES,   AND    MACHINERY.      427 

white  grubs.  Badly  infested  fields  may  even  be  ploughed  more 
than  once,  and  in  different  directions,  just  to  give  the  chickens 
an  opportunity  of  picking  up  the  insects.  I  have  seen  flocks  so 
well  trained  that  whenever  the  plough  harness  was  put  upon  the 
horse  they  gathered  together,  waiting  until  he  was  taken  to  the 
field. 

Turkeys  are  exceedingly  useful  where  grasshoppers  are  to  be 
dealt  with,  because  they  are  especially  fond  of  these  insects  ;  and 
for  the  same  purpose  Guinea-fowls  are  also  advisable.  Here 
again  the  practical  farmer  will  find,  with  a  little  observation,  just 
about  the  range  of  usefulness  of  the  various  fowls,  and  will  be 
able  to  adapt  his  cultivation  somewhat  to  their  peculiarities. 

In  the  matter  of  the  fertilizers  to  be  used  we  have  also  an  oppor- 
tunity for  careful  selection.  We  may  say  generally,  that  manure 
and  all  vegetable  matter  in  a  decaying  state  favors  the  develop- 
ment of  insects.  It  affords  both  food  and  lodgement  to  many 
species,  and  when  it  is  put  on  in  the  fall  or  winter  in  a  coarse 
condition,  it  is  a  direct  benefit  to  insects  that  hibernate,  even 
when  ploughed  under.  On  the  other  hand,  the  mineral  fertil- 
izers, especially  those  containing  a  considerable  percentage  of 
salt,  are  unfavorable  to  insects  of  all  descriptions,  and  to  some 
they  are  deadly.  Experience  has  shown  that  plant-lice  are  sus- 
ceptible to  the  action  af  the  salty  fertilizers,  and  that  cut-worms 
and  wire-worms  are  affected  by  them  to  a  considerable  extent. 
Among  corn  insects,  injury  from  the  root  web-worms  may  be 
entirely  avoided  by  using  the  mineral  fertilizers  instead  of  barn- 
yard manure,  if  fall  or  very  early  spring  ploughing  is  not  feasible. 
So  the  time  of  application  is  important,  as  is  the  amount  to  be 
applied.  For  instance,  in  land  infested  by  wire-worms  and  to  be 
put  into  corn,  the  best  time  for  the  application  is  just  after  it  has 
been  prepared  and  after  the  seed  has  been  planted.  Then  all 
the  potash  should  be  put  on,  in  the  form  of  kainit,  in  one  appli- 
cation, while  as  much  as  is  desirable  of  the  nitrogen  should  be 
put  on  in  the  form  of  nitrate  of  soda.  In  this  way  the  soil 
becomes  impregnated  with  a  rather  concentrated  salty  mixture 
which  is  fatal  to  many  of  the  insects.  The  same  amount  of  fer- 
tilizer distributed  in  several  applications,  or  put  on  the  ground  in 
fall,  or  when  vegetation  covers  it,  would  be  entirely  ineffective. 
Mineral  fertilizers  are  advisable  wherever  their  use  is  otherwise 


428  A  A'    ECONOMIC  ENTOMOLOGY. 

profitable,  and  are  always  to  be  preferred  to  decomposing  vege- 
table matter,  from  the  insect  stand-point.  The  details  of  the 
applications  to  be  made  are  found  where  the  insects  themselves 
are  treated.  Where  barn-yard  manure  must  be  used,  it  is  always 
a  good  plan  to  mix  it  with  air-slacked  lime,  land  plaster,  or  kainit, 
and  this  can  be  done  as  fast  as  it  is  made  in  the  stable.  It  will 
add  to  its  value,  will  hold  the  ammonia,  and  will  make  the  mixture 
an  undesirable  one  for  insects  to  live  in. 

Grass  land  may  be  kept  tolerably  free  from  undesirable  pests 
infesting  the  roots  by  using  as  fertilizer  a  mixture  of  one  hun- 
dred bushels  of  lime  and  one  ton  of  kainit  slaked  together.  This 
may  be  applied  in  the  spring,  and  will  act  as  a  stimulant  as  well 
as  destroy  many  of  the  insects  inhabiting  the  soil. 

There  are  yet  other  ways  in  which  we  can  head  off  insects  ;  for 
instance,  in  the  selection  of  the  time  of  planting.  It  happens 
frequently  that  insects  make  their  appearance  at  a  very  definite 
time,  and  in  the  ordinary  course  of  nature  have  only  a  few  days 
within  which  they  must  lay  their  eggs  and  provide  for  the  con- 
tinuance of  their  kind.  If  they  do  not  find  the  cultivated  food- 
plant,  they  are  compelled  to  make  use  of  some  substitute  wild 
plant,  on  which  they  do  not  thrive  as  well  ;  or  they  may  not  be 
able  to  oviposit  at  all,  and  a  large  proportion  will  perish  without 
being  able  to  reproduce  their  kind. 

When  the  life  history  of  a  seriously  injurious  insect  is  known, 
it  will  often  pay  to  adapt  our  farm  practice  so  as  to  prevent  injury. 
For  instance,  experience  has  proved  that  the  Hessian-fly  appears, 
ready  to  lay  eggs  for  a  late  fall  brood,  during  the  early  days  of 
September.  By  delaying  planting  until  after  the  middle  of  that 
month,  or  even  later  where  the  latitude  makes  this  feasible,  the 
insects  are  compelled  to  lay  their  eggs  in  grasses  other  than 
wheat,  or  in  the  volunteer  grain  that  they  find  in  fields  or  along 
the  roads. 

Cranberry  growers  take  advantage  of  their  knowledge  of  the 
life  history  of  the  Teras  infesting  that  crop  by  keeping  the  bogs 
covered  with  water  until  after  the  middle  of  May,  thus  compelling 
the  moths  to  lay  their  eggs  on  other  plants  belonging  to  the  same 
natural  family. 

In  a  similar  way  we  can  sometimes  induce  the  insects  to  ovi- 
posit in  a  trap  crop  planted  especially  to  attract  them  and  pro- 


INSECTICIDES,    PREVEXTIIES,    AXD    MACinXERY.      ^zQ 

tcct  the  staple.  An  example  of  this  is  the  practice  of  certain 
squash  growers,  w  ho  plant  early  summer  squashes  to  attract  the 
borers,  and  Hubbards  and  marrowfats  rather  late,  so  as  to  be 
unattractive  to  the  moths  as  compared  with  the  vigorous  early 
plants.  The  summer  varieties  may  be  taken  out  and  destroyed, 
with  all  their  contents  of  borers,  after  an  early  crop  has  been 
picked  from  them,  and  this  will  leave  the  later  varieties  free, 
while  it  also  accomplishes  the  destruction  of  an  entire  brood  of 
larva.  So  it  has  been  found  practicable  in  the  South  to  protect 
cabbages  from  the  attacks  of  the  harlequin  cabbage-bug  by 
planting  an  early  trap  crop  of  mustard,  to  which  the  insects  are 
attracted,  and  from  which  they  can  be  gathered  by  hand  or 
destroyed  by  spraying  with  pure  kerosene. 

An  instance  of  the  use  of  methods  of  cultivation  we  find  in  the 
practice  of  blackberry  growers,  who,  to  prevent  injury  from  the 
red-necked  canc-borer,  cut  off  during  the  latter  part  of  June  all 
the  shoots  then  above  ground,  and  either  gather  and  destroy,  or 
merely  allow  them  to  wilt  and  die.  The  beetles  have  all  disap- 
peared at  this  time  and  all  their  eggs  are  in  these  shoots.  The 
new  canes  that  come  up  after  this  trimming  become  sufficiently 
mature  and  are  in  sufficient  number  to  make  next  year's  crop, 
while  they  are  free  from  any  possible  beetle  attack. 

There  are  many  other  wavs  in  which  farm  practice  may  prevent 
injury  from  insects,  and  to  the  intelligent  farmer  these  methods 
will  commend  themselves  much  more  than  the  indiscriminate  use 
of  insecticides  after  damage  has  been  caused.  The  prevention  of 
attack  is  always  better  than  the  destruction  of  the  insects  after 
injury  has  been  accomplished,  and  some  of  these  methods  have 
the  advantage  of  effecting  a  permanent  reduction  of  the  injurious 
species.  Further  details  are  hardly  in  place  here,  but  what  has 
been  said  will  explain  the  reason  for  many  of  the  recommenda- 
tions made  in  the  body  of  the  work. 


430  AN  ECONOMIC  ENTOMOLOGY, 

CHAPTER    III. 

PREVENTIVES. 

There  are  many  insects  seriously  injurious  to  trees  that  are 
difficult  to  reach  with  insecticides  of  any  kind,  and  are  with  diffi- 
culty destroyed  in  any  way,  and  first  among  these  are  borers, 
whatever  the  order  to  which  they  belong.  It  has  been  already 
indicated  under  various  headings  what  measures  are  available  for 
preventing  and  curing  injury,  but  perhaps  a  grouping  of  what 
may  be  termed  preventive  measures  will  be  of  some  use.  It  is 
the  fruit  grower  that  suffers  most  from  boring  insects,  and  while 
small  fruits  are  often  attacked,  the  most  serious  and  permanent 
injury  is  done  to  trees.  Peach-trees  are  girdled  at  or  near  the 
surface  of  the  ground  by  a  Lepidopterous  borer  ;  apple,  pear, 
quince,  and  similar  trees  are  attacked  on  almost  all  parts  of  the 
trunk,  yet  preferably  near  the  base,  by  Coleopterous  borers,  and 
almost  all  our  fruit-trees  are  subject  to  the  attack  of  bark-beetles. 
Many  of  our  shade-trees  also  suffer  from  boring  insects  of  various 
descriptions.  It  is  often  easier  to  keep  these  borers  out  than  it 
is  to  destroy  them  after  they  once  get  in,  and  to  do  that  we  must 
resort  to  mechanical  measures.  The  simplest  as  well  as  most 
effective  method  is  the  use  of  a  wire  mosquito  netting  on  apple, 
quince,  and  similar  trees.  The  parents  of  both  the  round  and 
flat-headed  borers  infesting  these  trees  are  quite  large  insects,  un- 
able to  oviposit  or  lay  their  eggs  through  the  meshes  of  an  ordi- 
nary mosquito  netting,  provided  it  be  kept  at  least  half  an  inch 
from  the  bark  at  all  points.  In  this  way  apple-orchards  and  those 
subject  to  the  same  kind  of  injury  may  be  effectively  protected, 
and  trees  once  netted  will  need  little  attention,  except  an  occasional 
retying,  for  several  years.  The  wire  netting  should,  ot  course, 
be  thoroughly  painted  in  the  first  place,  and  should  have  suffi- 
cient lap,  when  cut,  to  allow  of  considerable  growth  of  the  tree. 
The  top  must  be  closed  by  being  tied  tightly  to  the  trunk,  or  the 
interval  between  the  trunk  and  netting  must  be  filled  with  cot- 
ton or  some  similar  material,  that  the  insects  cannot  crawl  under 
it.     In  like  manner  the  ground  must  be  hilled  around  the  wiring 


INSECTICIDES,    rRElEXTIVES,   AND    MACHINERY.      431 

at  the  base,  to  prevent  the  entrance  of  insects  at  that  point.  If 
it  should  happen  that  trees  are  already  infested,  the  beetles  that 
come  from  the  trunk  will  be  unable  to  get  away  and  should  be 
killed  through  the  netting. 

Wrapping  with  newspapers  or  tarred  paper  is  another  satis- 
factory and  tolerably  effective  measure.  Newspapers  will  last  a 
season  without  being  renewed  ;  tarred  paper  may  last  longer,  but 
will  need  retying.  The  tar  adds  nothing  to  the  effectiveness  of 
the  paper,  but  serves  to  protect  it  and  make  it  more  lasting.  The 
covering  must  be  complete,  so  that  the  insects  cannot  get  be- 
neath it.  Here  also  any  insects  already  in  the  trunk  of  the  tree 
will  be  kept  in  and  perish.  This  is  applicable  to  all  insects,  what- 
ever the  size,  and  will  prove  effective  in  proportion  to  the  care 
used  in  fastening  the  paper  in  place. 

Instead  of  these  materials,  the  German  raupenleim  or  the 
American  dendrolene  may  be  applied.  Both  are  crude  petro- 
leum products,  and  are  in  the  nature  of  an  impure  vaseline,  more 
or  less  greasy,  smooth,  of  a  butter-like  consistency  at  ordinary 
temperatures,  and  absolutely  resisting  wash  by  rains.  Applied 
three-sixteenths  of  an  inch  thick  or  more  to  the  surface  of  the  tree 
to  be  protected,  they  will  last  an  entire  season  without"  renewal. 
The  raupenleim  hardens,  after  a  time,  into  a  crust,  while  the 
dendrolene  tends  rather  to  become  absorbed.  No  insect  will 
rest  upon  these  materials  long  enough  to  lay  an  ^%%,  and  no  larva 
can  bore  through  them  to  reach  the  trunk  ;  hence  one  thorough 
application  is  an  effective  protection  against  borers  of  all  kinds, 
bark-beetles  as  well  as  others.  As  against  the  smaller  species, 
the  materials  answer  to  destroy  the  borers  already  in  the  tree  by 
preventing  them  from  coming  out  through  the  bark.  Applied 
around  the  base  of  peach-trees,  borers  may  be  kept  out,  and,  of 
course,  no  scale  insect  can  set  where  they  are  used.  Like  all 
other  mechanical  protections,  they  are  effective  in  proportion  as 
they  form  a  complete  covering  to  the  bark,  and  probably  in  no 
other  way. 

Either  raupenleim  or  dendrolene,  particularly  the  latter,  is 
effective  in  preventing  injury  by  canker-worms  or  other  insects 
that  crawl  up  the  trunk  to  reach  the  leaves,  whether  in  the  moth 
state  to  oviposit  or  in  the  caterpillar  state  to  feed.  A  broad  band 
of  dendrolene,  put  on  early  in  the  spring,  will  absolutely  pre- 


432  AX  ECONOMIC   ENTOMOLOGY. 

vent  injury  by  canker-worms,  because  it  hinders  the  female  from 
reaching  the  branches  to  lay  her  eggs.  In  the  same  way,  trees 
cleared  during  the  winter  of  the  ^^^  masses  of  the  vaporer  moth 
or  of  the  sacs  of  the  bag-worm  may  be  kept  cleared  during  the 
year  following  by  a  band  of  these  materials.  It  is  said  that 
raupenleim,  under  the  influence  of  cold  nights,  becomes  too 
hard  to  be  effective,  but  this  is  not  the  case  with  dendrolene. 

A  word  of  caution  must  be  added.  Both  of  these  materials 
penetrate  to  some  extent,  the  dendrolene  more  than  the  rau- 
penleim, because  it  never  becomes  hard  and  never  dries.  On 
thin-barked  or  very  young  trees,  if  it  is  left  on  continuously, 
it  will  not  only  check  the  growth  of  the  bark  and  kill  the 
outer  layer,  but  may  destroy  the  tree  itself.  This  is  especially 
true  of  peach-trees,  and  on  such  the  materials  should  not  be 
applied  very  heavily,  and  should  be  washed  off  after  midsum- 
mer with  some  potash  wash.  Both  raupenleim  and  dendrolene 
dissolve  readily  in  benzine,  turpentine,  or  kerosene,  and  they 
combine  easily  with  any  caustic  ;  hence  the  bark  can  be  cleared 
without  very  much  trouble  after  the  danger  season  is  over.  On 
old  trees,  where  the  outer  layer  of  bark  is  no  longer  active,  less 
danger  is  to  be  apprehended.  Where  trees  are  banded  against 
the  canker  worm  or  similar  insects,  the  easiest  way  would  be  to 
first  tack  a  band  of  heavy  wrapping-paper  close  to  the  trunk  and 
apply  the  material  to  that.  It  should  be  smeared  over  the  edges 
of  the  paper  to  the  bark,  so  as  to  prevent  any  insect  from  getting 
under  it,  and  when  the  danger  season  is  over  this  band  can  be 
cut  away  without  trouble,  leaving  only  a  narrow  ring  of  the 
smear,  which  could  do  no  harm.  Where  protection  against 
borers  only  is  sought,  all  injury  can  be  avoided  by  mixing 
the  dendrolene  with  dry  earth  or  with  land  plaster,  weight  for 
weight,  which  will  not  reduce  its  value  as  a  covering,  but  will 
diminish  its  penetrating  qualities. 

Lime  is  an  exceedingly  good  preventive,  applied  in  the  form 
of  whitewash.  Fruit-trees  that  have  the  trunks  whitewashed 
early  in  spring  will  be  apt  to  remain  measurably  free  from  scale 
attack,  and  if  it  is  applied  fresh,  a  great  many  of  the  scales  already 
upon  the  trunk  will  be  killed.  It  is  an  advisable  thing,  when 
Bordeaux  mixture  is  applied,  to  use  plenty  of  lime,  especially 
upon  the  trunks  and  branches  of  the  trees,  because  no  scale  in- 


INSECTICIDES,    PKEVEXTIVES,   AND    MACHINERY.      433 

sect  can  or  will  set  on  a  lime-covered  surface.  Of  course,  lime 
washes  away  readily,  and  must  be  renewed  from  time  to  time  to  be 
thoroui;hly  effective.  Keeping  it  up  until  midsummer,  however, 
is  usually  sufficient,  except  against  scales  that  have  several  broods. 

Under  the  heading  of  "preventive  measures,"  keeping  the 
trees  clean,  free  from  all  sorts  of  abnormal  growth  and  from  loose 
bark,  liiay  be  counted.  Winter  washing  the  trunks  with  a  strong 
potash  solution  is  always  advisable.  This  cuts  away  anything  in 
the  form  of  fungus,  moss  or  lichen  growths,  and  leaves  the  bark 
fresh  and  glossy  for  the  season  following.  It  also  destroys 
many  of  the  insects  hibernating  upon  the  trunk  in  any  stage. 

Finally,  the  most  important  of  all  preventive  measures  is  good 
farming.  Keep  crops  of  all  kinds  in  the  most  vigorous  possible 
condition,  with  plenty  of  readily  available  plant  food,  and  in 
orchards  allow  no  dead  wood  of  any  kind  to  remain  over  winter. 
Dead  or  dying  branches  should  be  cut,  carted  out,  and  burnt 
before  the  first  warm  spell  of  spring,  and  dying  trees  should  meet 
the  same  fate.  There  will  then  be  nothing  to  encourage  insects 
either  to  come  into  the  orchard  or  to  remain  there  if  accidentally 
brought  in.  Good  farming,  it  may  again  be  said,  is  the  very  best 
possible  preventive  of  insect  injury. 

It  is  necessary  to  merely  mention  that  printer's  ink,  birdlime, 
and  perhaps  other  substances  have  been  recommended  for  band- 
ing trees,  or  for  the  purposes  for  which  raupenleim  and  den- 
drolene  have  been  recommended.  Hydraulic  cement  or  "  water 
lime"  mixed  with  skim-milk,  to  form  a  thick  paint,  makes  a 
covering  that  will  last  an  entire  season. 

To  prevent  climbing  cut  worms,  canker-worms,  or  similar 
creatures  from  ascending  a  tree,  a  band  of  cotton  batting  can  be 
satisfactorily  used  in  many  cases  as  follows  :  Make  the  band  from 
eight  to  twelve  inches  wide  and  long  enough  to  go  round  the 
trunk  and  lap  two  inches.  Tie  tightly  at  the  bottom  of  the  band, 
smooth  side,  if  any,  to  the  trunk,  and  then  turn  down  the  band 
from  the  top,  like  an  inverted  funnel.  This  prevents  the  inner 
side  of  the  funnel  from  matting  when  wet  by  rains,  and  under 
ordinary  circumstances  forms  a  complet.'^  bar  to  the  ascent  of 
insects.  A  band  of  this  kind  above  a  coating  of  some  kind,  to 
prevent  the  bark  from  being  eaten,  ought  to  protect  even  very 
voung  orchards  from  climbing  cut-worms. 

2S 


434  AN  ECONOMIC   ENTOMOLOGY. 

CHAPTER    IV. 

INSECTICIDES. 

Some  of  the  principles  governing  the  apphcation  of  insecticides 
have  been  referred  to  and  stated  in  previous  parts  of  this  work, 
but  it  is  deemed  advisable  to  refer  specifically  to  the  different 
kinds  of  materials,  and  to  mention  the  range  of  the  most  useful 
among  those  now  upon  the  market.  Broadly  speaking,  we  may 
say  that  insecticides  are  of  two  kinds, — those  that  kill  by  being 
eaten,  or  stomach  poisons,  and  those  that  kill  by  contact.  Some 
substances,  such  as  hellebore  and  tobacco,  belong  to  both  cate- 
gories,— that  is  to  say,  they  are  poisonous  when  eaten,  and, 
when  properly  applied,  also  kill  by  contact. 

Oi  the  stomach  poisons,  none  are  in  more  general  use  or  of 
greater  importance  than  the  preparations  of  arsenic,  and  of  these 
three  only  need  be  considered  here, — Paris  green,  or  arsenite  of 
copper,  London  purple,  or  arsenite  of  lime,  and  "gypsine,"  or 
arsenate  of  lead.  All  of  these  have  very  much  the  same  range 
of  usefulness,  and  may  be  treated  together.  In  each  case  the 
active  principle  is  arsenic,  and  the  combination  with  the  other 
material  is  simply  to  put  it  into  an  insoluble  form  to  prevent 
injury  to  the  plants ;  for  arsenic  is  quite  as  violent  a  poison  to 
plants  as  it  is  to  animals.  In  Paris  green  the  arsenic  is  in  combi- 
nation with  copper,  and  in  many  cases  we  get,  besides  the  in- 
secticide effect,  a  direct  influence  upon  fungi.  An  average  good 
sample  contains  about  as  follows  : 

Per  Cent. 

Moisture 74 

Arsenious  oxide  (AsgOg) 68.82 

Copper  oxide  (CuO) 30.59 

100.15 

A  small  quantity  of  the  arsenic  remains  here  in  a  soluble  con- 
dition, especially  when  the  weather  is  warm  ;  hence  we  frequently 
find  that  spraying  on  a  hot  day  is  much  more  likely  to  burn  the 
foliage  than  when  done  on  a  cool  day,  or  late  in  the  afternoon. 


IXSECTICIDES,    PKEVEXTIVES,   AXD    MACJILYEKY.      435 

This  is  due  entirely  to  the  fact  that  the  water  appHed  to  the  leaves 
becomes  rapidly  warmed  up  by  the  sun  before  evaporating,  and 
meanwhile  dissolves  every  particle  of  soluble  arsenic,  bringing  it 
into  direct  contact  with  the  vegetable  surface  upon  which  it  rests. 
In  London  purple  we  have  a  decidedly  smaller  percentage  of 
arsenic,  as  will  be  seen  by  the  following  analysis  : 

Per  Cent. 

Moisture 3.27 

Arsenious  oxide  (AsgOg) 41 -44 

Lime  (CaO) 24.32 

Iron  and  alumina  (FegOaT  AI2O3) 3.37 

Sulphuric  acid  (SO3) 31 

Dye,  by  difference 27.29 

100.00 

More  of  the  arsenic  is  soluble  here,  which  explains  why  London 
purple  is  more  apt  to  burn  foliage  than  Paris  green.  Both  the 
insecticides  just  mentioned  can  be  made  entirely  harmless  to 
foliage  by  adding  weight  for  weight  of  caustic  lime  when  mixing. 
That  is  to  say,  in  preparing  the  poison  for  use,  take  one  pound 
of  Paris  green  or  of  London  purple  and  one  pound  of  quick- 
lime ;  add  water  enough  to  slake  the  lime,  and  mix  thoroughly 
while  hot,  so  as  to  incorporate  lime  and  poison  completely.  This 
will  fix  with  the  lime  every  particle  of  the  soluble  arsenic  con- 
tained in  the  mixture,  and  it  can  then  be  diluted  with  water  and 
applied  at  almost  any  reasonable  strength  without  much  danger 
of  injury  to  even  the  most  tender  foliage. 

Paris  green,  containing  the  greatest  percentage  of  arsenic,  will 
go  furthest  for  insecticide  purposes,  and  for  most  insects  will  be 
effective  when  applied  in  liquid  form  at  the  rate  of  one  pound  in 
two  hundred  gallons  of  water.  Used  against  the  plum  curculio, 
or  against  the  codling-moth,  one  pound  in  one  hundred  and 
seventy-five  gallons  is  more  effective.  Used  against  the  potato- 
beetle,  one  pound  in  one  hundred  gallons  is  most  satisfactory. 
Used  in  a  dry  condition,  the  Paris  green  may  be  applied  without 
any  danger  of  injury,  provided  the  application  be  made  in  a  very 
fine  dust.  It  can  be  mixed  with  plaster  of  Paris,  flour,  or  air- 
slaked  lime,  and,  practically,  one  pound  of  Paris  green  in  one 
hundred  pounds  of  lime  or  plaster  makes  a  good  mixture,  effec- 
tive for  insects  of  almost  all  kinds  and  harmless  to  plants.     There 


436  AN  ECOXOMIC    EXTOMOLOGY. 

are  some  instances  when  the  dry  apphcation  is  to  "be  preferred 
to  the  spray,  as  in  the  cotton-field  against  the  cotton-worm  and 
against  potato-beetles.  The  essential  points  in  powder  applica- 
tions, where  the  substance  is  to  be  used  undiluted,  is  to  have  it 
perfectly  dry,  and  to  put  it  on  very  thinly  and  evenly.  Paris 
green,  to  have  the  greatest  effect,  should  be  extremely  fine  ;  the 
finer  the  particles  the  more  effective  will  be  the  application  and 
the  greater  the  surface  covered  by  an  equal  amount  of  poison. 
Where  used  in  water  it  remains  in  suspension  better  in  propor- 
tion as  the  material  is  in  good  mechanical  shape  ;  the  larger  the 
grains  the  more  rapidly  they  sink  to  the  bottom.  In  applying 
Paris  green  it  must  always  be  remembered  that  there  is  no  solu- 
tion, but  merely  a  mechanical  mixture  ;  that  the  substance  is 
heavy  and  will  sink  to  the  bottom  unless  it  be  kept  constantly 
stirred. 

London  purple  is  a  waste  product,  and  its  composition  is  not 
in  all  cases  quite  the  same,  but  under  ordinary  circumstances 
does  not  vary  much  from  the  analysis  given.  It  should  always 
be  mixed  with  lime,  as  already  described,  before  being  used.  It 
is  effective  against  most  insects  at  the  rate  of  one  pound  in  one 
hundred  and  eighty  gallons  of  water.  Against  the  plum  curculio 
or  the  codling-moth,  one  pound  in  one  hundred  and  fifty  gallons 
of  water  is  more  effective  ;  while  against  the  potato-beetle,  one 
pound  in  one  hundred  gallons  is  generally  satisfactory.  London 
purple  can  also  be  used  dry,  but  should  never  be  used  pure  in  this 
way,  because  even  a  small  degree  of  moisture  may  have  the  effect 
of  liberating  some  of  the  free  arsenic  and  causing  injury.  It  is 
best  combined  with  air-slaked  or  dry  hydrate  of  lime,  and  is 
then  both  effective  and  harmless.  The  material  is  very  much 
finer  and  lighter  than  Paris  green,  and  remains  in  suspension  in 
water  very  much  better ;  therefore,  less  stirring  is  required  ;  but 
all  the  other  points  that  have  been  referred  to  under  Paris  green 
apply  here  equally  well. 

Arsenate  of  lead,  or  "gypsine,"  stands  on  a  different  footing, 
yet  acts  in  the  same  way.  This  must  be  made,  as  used,  of  arse- 
nate of  soda  four  ounces  and  acetate  of  lead  eleven  ounces,  or 
in  that  proportion  for  a  larger  or  smaller  quantity.  These  sub- 
stances dissolve  readily,  and  the  quantities  given  can  be  mixed 
in  one  gallon  of  water  for  dilution,   or  can  be  placed   in  one 


INSECTICIDES,    PKEVEX'JHES,   AND    MACHINERY.      437 

hundred  gallons  ready  for  use.  This  combination  has  the  ad- 
vantage of  being  harmless  to  foliage,  whatever  the  strength  in 
which  it  is  applied.  The  fifteen  ounces  of  mixed  arsenate  and 
acetate  have  been  apjjlied  to  peach-trees  in  two  gallons  of  water, 
antl  this — the  most  delicate  and  sensitive  of  all  fruit-foliage — 
was  absolutely  uninjured.  The  mixture  is  less  poisonous  than 
either  Paris  green  or  London  purple,  containing,  as  it  does,  a 
smaller  percentage  of  arsenic  in  an  absolutely  insoluble  form  ; 
but  it  is  also  much  cheaper,  and  to  obtain  the  same  effects  costs 
just  about  the  same,  or  a  trifle  less.  As  a  rule,  four  ounces  of 
arsenate  of  soda  and  eleven  ounces  of  acetate  of  lead  will  suffice 
for  one  hundred  gallons  of  water,  and  this  mixture  will  be  effec- 
tive against  most  insects,  including  the  elm-leaf-beetle  in  all  its 
stages,  the  various  web-worms,  canker-worms,  and  the  codling- 
moth.  Where  a  rapid  effect  is  necessary,  the  quantity  can  be 
doubled.  Where  a  great  deal  of  the  mixture  is  to  be  used,  it 
can  be  made  in  a  concentrated  form,  and  a  proper  proportion  of 
the  stock  added  to  each  tank  of  water  as  used.  Arsenate  of 
lead  does  not  dry,  but  forms  an  almost  pure  white,  pasty  pre- 
cipitate. It  remains  well  in  suspension,  and  needs  but  little 
stirring.  Its  great  advantage  is  its  harmlessness  to  plant-life  of 
all  kinds.  It  should  not  cost  above  eight  cents  per  pound  for 
arsenate  of  soda  and  fourteen  cents  per  pound  for  acetate  of 
lead,  or  about  thirteen  cents  per  fifteen  ounces  for  the  arsenate 
of  lead. 

Pure  white  arsenic  has  been  recommended,  and  is  used  with 
satisfaction  by  some  agriculturists.  It  is  certainly  the  cheapest 
as  well  as  the  most  active  of  the  poisons  of  this  class.  It  is  effec- 
tive at  the  rate  of  one  pound  in  from  two  hundred  and  fifty  to 
five  hundred  gallons  of  water,  the  latter  strength  corresponding 
to  Paris  green  at  one  pound  in  two  hundred  gallons,  and  the 
former  to  one  pound  in  one  hundred  gallons.  It  contains  much 
more  soluble  arsenious  acid  than  either  of  the  other  mixtures,  and 
will  burn  foliage  severely  unless  mixed  with  twice  its  own  weight 
of  quick-lime.  If  that  be  done,  however,  an  insoluble  arsenite 
of  lime  is  obtained  which  is  exceeding  effective  and  can  be  used 
as  safely  as  any  of  the  other  mixtures. 

There  is  sometimes  a  little  difficulty  in  making  a  water  mixture 
stick  to  very  smooth,  or  spread  over  very  hairy  leaves,  and  in 


438  AN  ECONOMIC   ENTOMOLOGY. 

such  cases  the  addition  of  one  pound  of  soap  to  every  forty  or 
fifty  gallons  of  water  will  aid  matters  considerably.  The  mixture 
will  spread  much  more  completely,  and  will  adhere  even  to  very 
smooth  or  feathery  foliage  if  a  fine  spray  nozzle  is  employed. 
One  quart  of  molasses  or,  better,  glucose  in  every  fifty  gallons 
of  water  will  also  greatly  increase  the  adhesive  and  lasting  quali- 
ties of  any  mixture  employed. 

These  arsenical  poisons  act  only  through  the  stomach,  and  no 
insects  are  able  to  resist  them  entirely,  although  some  bear  a 
considerable  amount  without  showing  immediate  effects.  When- 
ever they  are  available,  it  will  pay  to  use  them  to  the  exclusion 
of  other  materials.  There  is  no  other  stomach  poison  that  com- 
pares with  them.  And  here  it  may  be  advisable  to  say  a  few  words 
concerning  a  great  many  ' '  harmless' '  insecticides  placed  upon 
the  market. 

As  a  matter  of  fact  almost  all  the  commercial  insecticides  other 
than  pastes  or  soaps  contain  arsenic  in  some  form  or  shape,  and 
this  is  in  most  instances  the  killing  agent.  It  is  also  quite  true 
that  under  ordinary  circumstances  the  preparations  are  ' '  harm- 
less" to  man,  because  in  so  diluted  a  form.  As  these  poisons 
are  used  upon  plants,  the  proportion  is  so  small  that  danger  to 
life  is  not  to  be  anticipated,  except  as  a  result  of  the  grossest 
carelessness  ;  hence,  strictly  speaking,  the  mixtures  are  ' '  harm- 
less," though  containing  arsenic.  The  purchaser,  however,  usu- 
ally pays  at  least  three  prices,  and,  in  addition,  freight  charges 
upon  a  mass  of  inert  diluting  matter. 

There  is  another  way  of  using  the  arsenites  which  should  be 
briefly  referred  to  here, — i.e.,  in  a  poisoned  bran  mixture,  to 
attract  cut-worms  and  some  other  insects  to  a  deadly  feast.  Mix 
one  pound  of  Paris  green,  or  half  as  much  white  arsenic,  with 
fifty  pounds  of  bran,  making  the  combination  as  perfect  as  pos- 
sible ;  then  add  water  enough  to  moisten  thoroughly,  so  that  the 
mixture  can  be  ladled  out  with  a  spoon  without  dripping.  A 
little  sugar  or  molasses  in  the  water  makes  the  mass  rather  more 
adhesive  and  lasting,  but  apparently  no  more  attractive  to  the 
insects.  How  this  mixture  should  be  used  will  be  found  stated 
in  those  cases  where  its  employment  is  indicated. 

Bichloride  of  mercury,  or  "corrosive  sublimate,"  is  an  ex- 
tremely violent  poison,  of  which  some  use  has  been  made,  but 


IXSECTIC/DES,   PREVENTIVES,   AND    MACHINERY.      439 

generally  with  only  small  satisfaction.  It  is  a  deadly  poison 
and  effective  against  insects,  but,  unfortunately,  is  just  as  injurious 
to  plants,  and  the  limit  of  effectiveness  as  between  plants  and 
insects  is  so  narrow  as  to  render  its  use  undesirable  in  most  cases. 
It  is  valuable  only  in  those  few  instances  where  it  is  desirable  to 
poison  a  prepared  food  or  bait,  and  its  use  is  not  advised,  except 
in  special  cases  where  particular  directions  are  given. 

The  Bordeaux  mixture,  though  primarily  a  fungicide,  has 
excellent  insecticide  qualities  in  certain  cases,  and,  among  others, 
it  seems  to  be  almost  a  specific  against  flea-beetles.  This  is  an 
important  feature,  and  renders  its  use  doubly  valuable  on  pota- 
toes, egg-plants,  tomatoes,  and  other  crops  susceptible  to  flea- 
beetle  attack.  Either  Paris  green,  London  purple,  or  white 
arsenic  may  be  added  to  the  Bordeaux  mixture  where  a  com- 
bined insecticide  and  fungicide  is  desired,  but  Paris  green  is  the 
best.  London  purple  only  can  be  added  to  the  ammoniacal 
carbonate  of  copper,  since  the  ammonia  in  the  fungicide  acts  as 
a  solvent  to  the  arsenic  in  Paris  green.  Either  of  the  fungicides 
may  be  treated  as  replacing  water,  in  determining  the  amount  of 
the  insecticide  to  be  used. 

The  formula  for  the  Bordeaux  mixture  is  as  follow's  : 

Sulphate  of  copper 6  pounds. 

Quick-lime 4  pounds. 

Water 22  gallons. 

Dissolve  the  copper  sulphate  in  one  gallon  of  hot  waiter,  and 
in  another  vessel  slake  the  lime  with  a  gallon  of  water  ;  add  the 
milk  of  lime  slowly  to  the  copper  solution,  stirring  constantly, 
and  strain  through  a  sieve  or  coarse  gunny  sack  ;  finally,  add 
twenty  gallons  of  water,  and  the  mixture  is  ready  for  use.  This 
gives  the  standard  full-strength  mixture,  and  half  strength  or 
other  proportionate  strengths  are  produced  by  simply  adding 
more  water. 

The  ammoniacal  solution  of  copper  carbonate,  or  "cupram," 
is  made  as  follows  : 

Carbonate  of  copper 5  ounces. 

Ammonia  water  (twenty-six  per  cent,  strength)  .    3  quarts. 
Water 30  gallons. 


440  AN  ECONOMIC   ENTOMOLOGY. 

Wet  up  the  copper  carbonate  in  a  quart  of  water,  add  to  it  the 
ammonia,  and  when  completely  dissolved  and  diluted  with  the 
water  the  compound  is  ready  for  use. 

Holding  a  sort  of  intermediate  position  between  stomach  and 
contact  poisons  are  powdered  white  hellebore  and  tobacco,  both 
of  which  may  be  used  pure  in  the  form  of  either  a  finely  ground 
powder  or  a  decoction.  Hellebore  has  a  very  narrow  range  of 
effectiveness,  and  is  particularly  useful  only  against  saw-fly  larvae 
like  the  "  currant-worm."  If  used  dry,  it  can  be  dusted  on  pure 
or  mixed  with  twice  its  own  weight  of  land  plaster  or  cheap 
flour,  and  will  kill  by  being  eaten  or  by  coming  into  contact  with 
the  insects.  If  a  spray  is  preferred,  it  is  generally  effective  within 
its  range  at  the  rate  of  one  ounce  in  two  quarts  of  water,  and 
sometimes,  in  the  case  of  young  saw-fly  larvae,  one  ounce  in  one 
gallon  of  water  will  be  sufficient.  The  material  should  be  steeped 
in  one  pint  of  boiling  hot  water,  and  the  cold  water  added  grad- 
ually. The  sediment  can  be  sprayed  on  with  the  liquid,  or  it 
can  be  thrown  away  and  only  the  extract  used.  The  decoction, 
at  the  rate  of  two  ounces  in  one  gallon  of  water,  has  been  highly 
recommended  against  the  cabbage-maggot,  but  the  reports  are 
too  contradictory  to  make  it  advisable  to  rely  upon  it  for  that 
purpose. 

Tobacco  has  a  very  much  wider  range  of  usefulness  ;  few  in- 
sects care  to  eat  of  it,  and  a  plant  thoroughly  sprayed  with  a  decoc- 
tion is  safe  from  the  attacks  of  flea-beetles  and  a  great  variety  of 
other  insects.  It  is  as  effective  against  the  saw-fly  larvae  as  is 
hellebore,  and  may  be  applied  in  much  the  same  way.  It  may, 
in  many  instances,  be  applied  at  the  base  of  plants  to  keep  off 
borers  and  root-feeders  generally  :  for  instance,  against  the  cab- 
bage-maggot, a  handful  of  tobacco  dust  at  the  base  of  each  plant 
will  usually  serve  as  a  tolerably  complete  protection.  It  is  as  a 
contact  poison  that  it  has  the  greatest  advantages,  and  it  may  be 
used  effectively  against  plant-lice,  either  in  a  dry  powder  or  in 
decoction.  If  used  as  a  powder,  it  is  very  important  that  it 
should  be  as  finely  ground  as  possible.  All  contact  poisons  kill 
through  the  stigmata,  or  spiracles.  The  fine  dust  makes  its  way 
through  the  breathing  pores  into  the  trachea,  and  sets  up  an  irri- 
tation which  results  in  the  death  of  the  insect.  The  coarse  par- 
ticles are  sifted  out  by  the  protective  structures  with  which  most 


LVSECT/C/DES,    PREVENTIVES,   AND    MACHINERY.      441 

insects  arc  sui)i)lied,  but  very  fine  j)articles  often  make  their  way 
tliroug^i  them.  It  is  important,  therefore,  if  tobacco  is  to  be 
used  dry,  that  it  be  in  as  fine  a  condition  as  it  is  possible  to  ob- 
tain. This  ai)pHes  even  where  it  is  used  on  the  surface  of  the 
ground  around  cabbage  plants.  As  a  decoction  its  range  of 
usefulness  is  greater.  It  is  fatal  to  a  large  number  of  caterpillars 
of  the  smaller  moths,  both  as  a  contact  and  as  a  stomach  poison, 
and  cranberry  growers  in  Massachusetts  use  great  quantities  of  it, 
at  the  rate  of  one  pound  to  one  gallon  of  water,  against  ' '  vine- 
worms"  and  "fire-worms."  Stems  and  other  refuse  are  just  as 
good  as  leaf  tobacco  for  this  purpose,  and  the  usual  method  is  to 
boil  down  the  coarsely  chopped  stems  until  a  deep  brown  extract 
is  obtained.  This  is  also  effective  against  plant-lice.  Ground 
tobacco  may  be  applied  on  the  surface  around  trees  infested  with 
root-lice,  and  the  result  will  be  beneficial,  especially  in  light  soil. 
As  against  the  peach-root  lice,  tobacco  has  been  employed  by 
first  trenching  around  the  base  of  a  moderately  large  tree  at  a 
distance  of  two  feet  from  the  trunk,  and  applying  the  tobacco 
dust  in  the  trench.  To  obtain  the  greatest  effect  there  should  be 
an  early  application  of  water,  either  in  the  form  of  rain  or  arti- 
ficially, to  dissolve  the  nicotine  and  carry  it  into  direct  contact 
with  the  root-feeding  lice.  As  tobacco  is  also  a  fertilizer,  quite 
rich  in  potash,  the  benefit  to  the  plants  is  doubled  where  the 
material  is  applied  to  the  soil.  As  a  stomach  poison  tobacco  is 
not  often  to  be  recommended,  but  as  a  contact  poison  it  is  fre- 
quently the  most  cleanly,  and  is  a  favorite  remedy  in  the  green- 
house. Besides  the  methods  already  indicated,  it  may  also  be  used 
in  the  form  of  smoke  ;  burning  or  steaming  it,  and  sending  the 
impregnated  vapor  into  the  conservatory  or  hot-house.  Tobacco- 
smoke  is  quickly  fatal  to  all  insects  that  breathe  it,  but  plants  ex- 
posed to  it  for  any  great  length  of  time  are  also  likely  to  suffer. 
No  specific  directions  as  to  the  quantity  of  tobacco  to  be  used 
can  be  given,  and  it  will  require  practical  experience  to  acquire 
the  knowledge  for  each  case.  Good  effects  can  be  obtained  in 
greenhouses  by  simply  placing  tobacco-stems  on  the  benches,  or, 
if  the  plants  are  potted,  the  pots  may  be  set  in  a  bedding  of 
stems,  or  the  stems  may  be  kept  upon  the  pipes  heating  the 
house,  and  this  will  give  a  sufficient  impregnation  to  the  air  to 
discourage  many  insects,   while  there  is   no  danger  to  plants. 


442  AN  ECONOMIC  ENTOMOLOGY. 

This  is  especially  effective  in  houses  that  are  kept  very  warm  and 
moist. 

Standing  on  much  the  same  plane  is  pyrethrum,  or  "  Persian 
insect  powder,"  or  "buhach,"  which  is  a  Californian  product. 
This  is  an  exceedingly  powerful  contact  poison,  usually  sold  in 
the  form  of  a  finely  ground,  yellowish  powder,  with  a  not  un- 
pleasant and  somewhat  pungent  smell.  Applied  pure  on  most 
insects  of  moderate  size,  and  especially  on  larvae,  it  quickly 
causes  convulsions,  and  in  most  cases  rapid  death.  It  may  be 
mixed  with  two  or  three  times  its  own  bulk  of  cheap  flour,  and  if 
the  mixture  is  kept  in  tight  jars  for  twenty-four  hours,  all  parts 
of  it  will  be  equally  effective.  It  is  especially  adapted  for  use 
against  plant-lice  on  a  small  scale,  but  is  somewhat  too  expensive 
for  use  in  the  field,  or  on  a  large  scale.  In  small  conservatories 
nothing  is  better  for  general  use,  except  against  scale  insects. 
Where  the  dry  powder  is  undesirable  for  any  reason,  use  a  de- 
coction of  an  ounce  in  a  gallon  of  water,  first  extracting  with  a 
quart  of  boiling  water  and  then  adding  cold  water.  Most  naked 
larvse  are  rapidly  affected  by  this  material  ;  and  while  it  is  espe- 
cially a  contact  poison,  yet  it  is  also  fatal  when  eaten,  except 
in  the  case  of  large  or  adult  insects. 

Among  the  contact  poisons  none  ranks  higher  than  kerosene, 
either  pure  or  made  into  an  emulsion  with  soap.  Pure  kerosene 
is  fatal  to  almost  all  insects  ;  it  is  extremely  penetrating,  and 
works  its  way  through  the  spiracles  into  the  body  cavity  and 
through  the  trachea  into  all  parts  of  it.  This  results  in  the  prompt 
choking  of  the  insect.  Pure  kerosene  is  more  or  less  injurious  to 
vegetation,  although  plants  vary  greatly  in  their  resistance,  and 
it  is  therefore  advisable  to  mix  it  with  water,  which  can  be  ac- 
complished by  first  emulsifying  with  either  soap  or  milk.  Prac- 
tically, milk  is  rarely  used  at  the  present  time,  as  the  soap 
formula  is  less  expensive  and,  in  general,  more  effective.  The 
following  is  the  method  of  preparing  the  emulsion  : 

Hard  soap,  shaved  fine one-half  pound. 

Water i  gallon. 

Kerosene     2  gallons. 

Dissolve  the  soap  in  boiling  water,  warm  the  kerosene  and  add 
the  boiling  hot  suds  to  it  ;  then  churn  with  a  force-pump  for  a 


/NSECriCIDES,   PREVENTIVES,   AND    MACHINERY.      443 

few  minutes,  and  we  get  first  a  milky  appearance,  which  yields 
rapidly  to  a  cream,  and  this  to  a  soft  butter-like  mass.  When 
cold,  this  will  adhere  to  glass  without  oiliness,  and  the  emulsion 
thus  made,  containing  sixty-six  per  cent,  of  kerosene,  may  be 
readily  mixed  with  water  to  any  extent.  It  is  also  quite  stable, 
and  will  remain  unchanged  for  a  considerable  time.  It  is  worthy 
of  note  that  the  emulsion  is  much  more  easily  made  with  soft 
water,  and  if  the  water  is  very  hard  a  permanent  emulsion  is 
difficult  to  procure.  It  is  always  advisable,  therefore,  to  use 
rain-water,  or  to  soften  the  hard  water  by  adding  soda  or  borax. 
Diluted  from  nine  to  twelve  times,  this  emulsion  is  very  effective 
against  plant-lice,  against  many  scale  insects,  and  against  a  great 
number  of  others  already  referred  to  in  previous  chapters.  Ex- 
cept in  its  pure  condition,  or  in  an  almost  undiluted  emulsion, 
scale  insects  are  not  killed  with  certainty  by  kerosene,  nor  are 
insect  eggs  often  affected  ;  yet  the  material  has  an  extremely  wide 
range,  and  is  among  the  most  useful  of  our  contact  insecticides. 

Another  kerosene  mixture  is  known  as  the  "  Cook  emulsion," 
made  as  follows  : 

Soft. soap I  quart. 

Water 2  quarts. 

Kerosene i  pint. 

Dissolve  the  soap  in  boiling  water  and  add,  boiling  hot,  to  the 
kerosene  ;  then  churn  as  for  the  previous  formula,  and  dilute 
with  an  equal  bulk  of  water  before  using.  This  is  effective  in 
many  cases  as  a  mere  soap-wash,  and  amounts  to  hardly  more 
than  the  addition  of  a  little  kerosene  to  strong  soapsuds.  The 
formula  is  not  recommended,  except  where  the  water  is  very 
hard  and  no  rain-water  is  available. 

A  combination  of  kerosene  and  pyrethrum  has  been  made  as 
follows  :  Percolate  through  one  pound  of  pyrethrum  one  gallon 
of  kerosene,  or  in  that  proportion,  and  use  the  extract  in  place 
of  the  pure  kerosene  : 

Hard  soap     i  pound. 

Kerosene  extract  of  pyrethrum i  gallon. 

Water i  gallon. 

Emulsify  as  before. 


444  ^^  ECONOMIC  ENTOMOLOGY. 

A  modification,  somewhat  more  easily  prepared,  is — 

Kerosene i  gallon. 

Hard  soap i  pound. 

Pyrethrum  powder i  pound. 

Water i  gallon. 

Dissolve  the  soap  in  boiling  water  ;  then  add  the  pyrethrum,  and 
stir,  while  continuing  to  boil,  five  minutes  ;  then  add  the  kerosene 
and  emulsify  as  before. 

This  mixture  has  been  found  effective  with  dilutions  of  from 
four  hundred  to  five  hundred  parts  of  water,  but  I  have  never 
been  able  to  secure  equally  satisfactory  results.  Indeed,  in  my 
experience  the  pyrethrum  adds  little  to  the  effectiveness  of  the 
emulsion.  •  Yet  I  would  not  discourage  experiments  with  the 
mixture,  which  may  work  better  in  other  hands. 

Kerosene  has  also  been  used  against  scale  insects  on  fruit- 
trees  in  winter  by  spraying  the  pure  material  and  in  about  ten 
minutes  setting  fire  to  it.  The  kerosene  burns  off  completely, 
taking  with  it  scales,  moss,  and  fungous  growths  generally.  This 
use  of  it  can  be  made  on  calm  days  only,  as  even  a  slow  current 
of  air  is  apt  to  blow  the  flame  from  one  side,  making  the  applica- 
tion ineffective. 

Gasoline,  a  much  lighter  oil,  is  useful  as  a  contact  insecticide 
in  a  limited  number  of  cases.  It  can  be  applied  to  textiles  in- 
fested with  ' '  moths, "  or  to  carpets  infested  with  ' '  carpet-beetles. ' ' 
It  is  very  penetrating,  kills  everything  it  touches,  and  evaporates 
rapidly  without  influencing  unfavorably  any  but  the  poorest  fab- 
rics. The  material  is  very  inflammable,  however,  and  this  should 
be  kept  constantly  in  mind  when  using  it. 

Soaps  of  various  descriptions  are  useful  contact  insecticides, 
and  act  through  the  stigmata,  or  breathing  pores,  by  clogging 
them  and  choking  the  insect  to  death.  It  is  essential,  to  obtain 
a  good  effect  from  a  soap  mixture,  that  the  application  be  ex- 
tremely thorough,  so  that  each  insect  receives  a  complete  coat- 
ing. There  is  a  great  variety  of  insecticide  soaps  on  the  mar- 
ket, but  they  all  act  in  much  the  same  way.  In  any  good  soap 
the  suds  are  capable  of  being  thinned  out  to  an  almost  impercep- 
tible film,  as  we  find  in  making  soap-bubbles,  and  this,  forming 
over  the  spiracles,  resists  the  entrance  of  air.     We  cover  the  in- 


INSECTICIDES,    PREVENriVES,    AND    MACHINERY.      445 

sects  with  a  fine  coating  of  soap,  which,  in  drying,  closes  up  the 
breathing  pores,  resulting  in  their  death.  It  is  thus  that  all 
soaps  act  when  used  against  j)lant-licc,  larvai,  or  adult  insects, 
and  it  is  readily  seen  that  extreme  thoroughness  of  application  is 
desirable. 

After  trying  a  large  proportion  of  the  soaps  on  the  market,  I 
have  found  nothing  more  effective  for  general  use  than  good 
whale-oil  soap  :  the  term  "whale  oil"  including  any  kind  of  fish 
oil  that  can  be  obtained  cheap.  The  soap  may  be  made  by  the 
farmer  himself,  according  to  the  formulas  given  on  every  package 
of  lye  ;  but,  practically,  the  material  is  sold  so  cheaply  that,  un- 
less labor  counts  for  nothing,  it  is  as  economical  to  buy  as  it  is  to 
make  it.  Whale-oil  soap  contains  a  considerable  amount  of 
caustic,  and  where  a  very  thick  suds  is  applied,  we  have  not 
only  the  effect  of  the  oil,  but  the  prolonged  effect  of  the  caustic 
contained  in  it.  It  is,  therefore,  especially  useful  for  destroying 
scale  insects,  against  which  caustics  alone  exercise  a  satisfactory 
effect.  In  whale-oil  soap  the  caustic  softens  or  lifts  the  scales, 
while  the  oil  in  the  soap  chokes  the  insect  to  death.  To  kill 
scales  on  trees  it  should  be  applied  during  the  winter,  when  the 
vegetation  is  dormant,  at  the  rate  of  two  pounds  in  one  gallon 
of  water.  To  destroy  plant-lice  and  most  other  insects  feeding 
upon  leaves,  an  extreme  application  is  one  pound  in  four  gallons 
of  water,  which  is  as  much  as  most  plants  will  safely  stand,  and 
which  is  also  effective  against  most  of  the  insects  upon  which  it 
can  be  used.  Most  plant-lice  yield  readily  to  one  pound  in  six 
gallons  of  water.  In  applying  this  material,  thoroughness  is  es- 
sential, and  it  is  the  disregard  of  this  necessary  feature  that  often 
leads  to  failure. 

It  sometimes  happens  that  a  really  good  fish-oil  soap  is  not 
obtainable  at  a  moderate  price,  and  where  it  is  desirable  that  a 
satisfactory  effect  be  obtained  against  resistant  scales  like  the 
San  Jose,  the  following  formula  will  make  an  effective  material  : 

Concentrated  lye ....  3>^  pounds. 

Water 8      gallons. 

Fish  oil     I     gallon. 

Dissolve  the  lye  in  boiling  water,  and  to  the  boiling  solution 
add  the  oil  ;  continue  to  boil  for  two  and  one-half  hours,  and  then 


446  AN  ECONOMIC  ENTOMOLOGY. 

allow  it  to  cool.  This  makes  an  exceedingly  caustic  soap,  which 
is  entirely  reliable  within  its  range  of  usefulness. 

Carbolic  acid  is  also  valuable  as  an  insecticide,  and  can  be  used 
in  the  form  of  an  emulsion  prepared  as  follows  :  one  pound  of 
hard  soap,  shaved  fine,  dissolved  in  one  gallon  of  boiling  water, 
into  which  one  pint  of  crude  carbolic  acid  is  then  poured,  and 
the  whole  mass  made  into  an  emulsion  with  a  force-pump,  used 
as  in  the  case  of  the  kerosene.  This  emulsion  remains  more  or 
less  stable  for  a  long  time,  and  can  be  diluted  with  thirty  parts 
of  water  for  effective  use  against  certain  classes  of  insects.  It  has 
been  recommended  for  cabbage-maggots,  and  at  the  strength 
given  will  not  injure  the  plants,  while  it  seems  to  be  fatal  to  the 
young  larvae.  It  is  probably  effective  on  soft-bodied  insects  in 
general,  but  it  undoubtedly  derives  a  considerable  proportion  of 
its  effect  from  the  presence  of  the  large  quantity  of  soap  in  the 
emulsion. 

Where  lime  is  to  be  used  as  a  repellent,  the  addition  of  one 
pint  of  crude  carbolic  acid  to  one  hundred  pounds  of  the  dry 
hydrate  will  increase  its  efficiency,  and  few  insects  will  touch 
plants  so  protected.  Among  these  few  insects,  however,  we 
find  the  rose-chafer. 

The  addition  of  carbolic  acid  to  the  whale-oil  soap  mixture  is  also 
advantageous  in  certain  cases.  One  ounce  of  crude  carbolic  acid 
in  each  gallon  of  whale-oil  soap  mixture  increases  its  effectiveness 
as  against  plant-lice  very  considerably.  One  pound  of  whale-oil 
soap  in  eight  gallons  of  water,  with  four  ounces  of  carbolic  acid 
added,  will  double  the  effectiveness  of  the  mixture  ;  but  as  the 
same  result  can  be  obtained  with  the  soap  alone  in  four  gallons 
of  water,  it  becomes  a  mere  question  of  cost  and  simplicity. 

The  whale-oil  soap  is  often  used  in  the  form  of  a  wash  to  pre- 
vent the  entrance  of  borers  into  fruit-trees,  and  in  such  cases  the 
addition  of  an  ounce  of  the  acid  in  a  gallon  of  soapsuds  seems  to 
add  to  its  efficiency.  It  is  claimed  that  trees  treated  with  such 
a  mixture  are  much  less  attacked  than  those  treated  with  the 
soap  alone.  A  little  lime  is  sometimes  added  to  a  liquid  of  this 
kind  to  make  it  more  permanent. 

Lime  alone  is  useful  as  an  insecticide  in  some  instances.  It 
has  been  found  effective  by  some  and  absolutely  useless  by 
others,   the  difference  in  result  being  often  due  to  a  difference 


INSECTICIDES,    PKEVEXTIVES,   AND    MACIIIXEKY.      447 

in  the  method  of  appHcation.  As  a  rule,  lime  may  be  said  to  be 
effective  in  proportion  as  it  is  caustic,  and  it  is  then  useful  against 
soft-bodied  insects.  The  best  way  to  prepare  it  is  to  add  just 
water  enough  to  stone  or  shell  lime  to  dry-slake  thoroughly,  then 
sift  and  apply  the  powder  as  soon  as  possible.  This  is  more 
caustic  than  air-slaked  lime,  and  will  burn  a  hole  through  the 
soft  body  of  most  larvae.  I  have  seen  it  applied  on  the  slugs  of 
the  potato-beetle  in  the  morning  while  they  were  a  little  moist, 
resulting  before  noon  in  their  complete  destruction.  So  it  may 
be  applied  to  cabbages,  and  will  in  the  same  way  destroy  the 
larvae  of  the  cabbage-butterfly.  Lime  is  one  of  the  best  mate- 
rials for  use  on  the  larvae  of  the  asparagus-beetle,  and  is  also 
effective  against  the  slimy  or  moist  saw-fly  larvae,  including  the 
"currant-worm."  To  obtain  the  best  effects  the  lime  should 
be  dry  and  caustic,  while  the  insects  upon  which  it  is  applied 
should  be  damp  or  slimy.  Wherever  a  particle  of  lime  sticks 
it  will  burn  a  hole  into  the  insect.  Few  insects  care  to  feed 
upon  limed  vegetation,  and  many  will  not  even  rest  upon  a  sur- 
face covered  by  it  ;  therefore,  lime  may  be  sometimes  used  as 
a  repellent.  Even  the  rose-chafer,  when  only  moderately  abun- 
dant, will  generally  avoid  lime-dusted  foliage.  Whitewashing 
the  trunks  of  trees  will  prevent  the  fixing  of  scale  insects  upon 
them,  and  will  discourage  borers  from  laying  eggs  on  or  boring 
into  them.  A  free  use  of  lime  in  every  direction  on  the  farm 
is  advised.  Against  the  striped  melon-beetles  use  one  pint  of 
turpentine  in  one  bushel  of  lime,  applying  freely  to  all  parts  of 
the  plant,  and  particularly  around  the  base.  This  will  keep  them 
off  in  most  cases. 

In  some  of  the  Pacific  States  resin  washes  are  much  used 
against  scale  insects,  apparently  with  excellent  success.  They 
have  not  been  as  satisfactory  when  used  in  the  East  ;  perhaps 
due  to  the  fact  that  the  insects  make  thicker  scales,  or  are  more 
completely  dormant  in  the  winter.  The  wash  which  has  given 
best  satisfaction  for  summer  use  is  made  according  to  the  follow- 
ing formula  : 

Resin 20  pounds. 

Caustic  soda  (seventy  per  cent,  strength)   ...  5  pounds. 

Fish  oil 3  pints. 

Water  sufficient  to  make 100  gallons. 


448  AN  ECONOMIC  ENTOMOLOGY. 

This  mixture  does  not  injure  the  trees  or  the  foliage,  and  is 
effective  against  young  scales.  It  kills  all  that  are  moving  about 
in  the  larval  condition,  and  also  destroys  recently  fixed  indi- 
viduals; but  it  is  ineffective  against  mature  scales  and  the  in- 
sects under  them.  It  acts  by  forming  a  thin  varnish  over  the 
scales,  thus  sealing  up  and  choking  them.  In  the  mealy-bugs 
and  cottony  scales  it  mats  up  and  seals  the  eggs  so  completely 
that  the  larvae  find  themselves  unable  to  emerge.  A  stronger 
wash,  used  in  winter,  is  made  according  to  the  following  formula  : 

Resin 30      pounds. 

Caustic  soda  (seventy  per  cent,  strength)      .  9      pounds. 

Fish  oil 4^-2  pints. 

Water  sufficient  to  make 100      gallons. 

To  make  this  mixture,  boil  all  the  ingredients  together  with 
twenty  gallons  of  water  until  thoroughly  dissolved,  adding  hot 
water  from  time  to  time,  but  not,  after  the  boiling  begins,  enough 
to  stop  it.  Three  hours  will  be  required  for  a  complete  mixture 
of  the  materials,  hot  water  to  make  fifty  gallons  being  gradually 
added  and  the  mixture  thoroughly  stirred  ;  after  this  the  balance 
of  one  hundred  gallons  can  be  added  in  cold  water.  This  is 
really  a  soap  varnish,  deriving  its  effect  from  the  caustic  and 
fish  oil,  while  the  resin  forms  an  impenetrable  covering.  The 
stronger  mixture,  or  "winter  wash,"  cannot  be  used  in  summer 
without  seriously  injuring  the  foliage. 

Another  wash  frequently  used  on  the  Pacific  coast,  and  found 
very  effective  against  the  San  Jos6  scale  and  other  insects,  is  a 
lime,  salt,  and  sulphur  mixture,  made  as  follows  : 

Unslaked  lime 50  pounds. 

Sulphur 25  pounds. 

Stock  salt 18  pounds. 

Water  sufficient  to  make 100  gallons. 

This  wash  will  do  great  damage  to  the  trees  if  applied  during 
the  growing  season,  and  should  be  used  only  in  winter.  All  the 
sulphur  and  half  the  lime  are  placed  in  a  kettle  and  twenty-five 
gallons  of  water  added,  after  which  the  contents  of  the  kettle 
are  boiled  briskly  for  an  hour  and  a  half,  or  until  all  the  sulphur 
is  thoroughly  dissolved.     The  solution,  which  at  first  is  yellow 


INSECTICIDES,   PREVENTIVES,   AND    MACHINERY.      449 

from  the  sulphur,  will  turn  very  dark  brown,  assuming  more  or 
less  of  a  reddish  tint,  and  will  finally  change  from  a  thick  batter 
to  a  thoroughly  liquid  condition,  the  product  being  ordinary 
sulphide  of  lime.  All  the  salt  is  added  to  the  remaining  lime 
and  the  latter  slaked,  after  which  the  slaked  lime  and  salt  are 
added  to  the  sulphide  of  lime  already  obtained,  boiled  an  hour 
longer,  the  whole  being  then  diluted  with  water  to  make  one 
hundred  gallons.  This  should  be  strained  before  application,  as 
it  does  not  form  a  perfectly  liquid  solution,  on  account  of  the 
considerable  quantity  of  undissolved  lime,  which  will  soon  settle 
to  the  bottom  unless  the  solution  is  constantly  stirred  while  being 
sprayed.  A  special  nozzle  with  a  rubber  orifice  is  used  for  spray- 
ing this  mixture  in  California. 

A  modification,  favored  in  Oregon,  is, — 

Unslaked  lime 100  pounds. 

Sulphur 100  pounds. 

Blue  vitriol 8  pounds. 

Place  all  the  sulphur  and  eighty  pounds  of  lime  in  a  kettle 
with  one  hundred  gallons  of  water  and  boil  slowly  until  the  sul- 
phur is  thoroughly  dissolved.  Dissolve  the  blue  vitriol  in  hot 
water,  add  to  the  remainder  of  the  slaked  lime,  and  mix  the 
whole  together.  This  wall  keep  any  length  of  time.  When 
ready  to  spray,  use  one  gallon  of  the  mixture  in  two  and  one- 
half  gallons  of  hot  water  and  apply  lukewarm.  It  may  be  used 
as  a  summer  wash  by  diluting  one  gallon  with  eight  or  ten  gallons 
of  water. 

These,  though  used  successfully  on  the  Pacific  coast,  have  not 
proved  as  satisfactory  in  the  East.  They  have  been  thoroughly 
tested  by  the  agents  of  the  Division  of  Entomology  of  the  United 
States  Department  of  Agriculture,  who  do  not  recommend  them 
on  the  Atlantic  coast.  On  the  other  hand,  it  should  be  said  that 
the  kerosene  emulsion  seems  to  be  much  less  effective  on  the 
Pacific  coast  than  it  is  in  the  East,  and  it  is  not  unlikely  that 
distinct  sets  of  remedies  must  be  used  under  different  climatic 
conditions,  these  to  be  ascertained  by  direct  experiments  in  the 
various  localities.  Progressive  farmers  will  make  it  a  point  to 
get  the  bulletins  of  the  Experiment  Stations  in  their  own  States, 
to  learn  from  them  those  facts  which  apply  particularly  in  their 

29 


45 o  AN  ECONOMIC  ENTOMOLOGY. 

own  localities.  The  resin  washes  will  not  act  well  where  frequent 
rains  and  much  dew  dissolve  the  varnish  formed  by  them  over 
the  scales. 

Caustic  potash  and  caustic  soda,  dissolved  in  water,  are  very- 
useful  winter  washes  for  fruit-trees.  They  can  be  used  at  the  rate 
of  one  pound  in  one  or  two  gallons  of  water,  and  will  destroy  all 
fungus  growth  and  most  of  the  common  scale  insects,  leaving 
the  bark  pure,  fresh,  and  glossy  for  the  following  season.  Inci- 
dentally, all  insects  hiding  under  loose  bark,  or  bark  scales,  are 
also  destroyed,  as  are  many  insect  eggs.  The  application  should 
be  confined  to  the  trunk  and  larger  branches,  as  there  is  danger 
to  green  bark  in  so  strong  a  wash,  and  no  foliage  or  active  plant- 
tissue  should  ever  be  so  treated. 

Water  alone,  either  very  hot  or  very  cold,  is  sometimes  a  use- 
ful insecticide.  Boiling  water  is  quickly  fatal  to  most  insects 
and  to  vegetation  as  well.  At  125°  it  is  effective  against  the  rose- 
chafer,  killing  it  instantly,  and  at  140°  it  is  still  safe  on  grape 
foliage.  At  160°  it  kills  all  vegetation  on  which  I  tried  it.  It 
has  been  applied  with  some  satisfaction  against  cabbage-worms 
without  injuring  the  plants,  and  perhaps  we  may  say  that  water 
at  a  temperature  of  125°  is  fatal  to  most  insects  and  harmless  to 
most  plants.  But  while  this  seems  a  very  convenient  and  cheap 
material,  there  are  really  grave  practical  difficulties  in  the  way  of  its 
general  use.  Even  boiling  water  applied  in  a  spray  becomes  too 
cold  twelve  inches  from  the  nozzle  to  be  of  any  effect ;  and  so 
rapidly  do  the  small  particles  lose  heat,  that  at  a  distance  of  three 
feet  it  is  reduced  to  atmospheric  temperature.  Its  usefulness  is 
limited,  therefore,  to  cases  where  it  can  be  applied  at  short  range 
by  a  sprinkler, — c.g,  on  cabbage-plants  ;  and  here  the  arsenites 
are  cheaper  and  more  certainly  effective. 

Very  cold  or  ice-water  is  effective  against  plant-lice  under 
some  circumstances,  and  I  have  known  of  trees  and  bushes  com- 
pletely cleared  by  one  application.  But  our  knowledge  of  the 
effects  of  cold  on  insects  and  plants  is  yet  too  small  to  make 
practical  recommendations  possible. 

Under  some  circumstances  vapors  can  be  made  useful.  Bi- 
sulphide of  carbon  volatilizes  readily  at  ordinary  temperatures  ; 
the  vapor  is  deadly  to  insects  of  all  kinds,  and  is  especially  useful 
against  species  infesting  stored  products,  like  grain  and  other 


INSECTICIDES,    PREVENTIVES,   AND    MACHINERY.      451 

seeds.  Where  used  in  bins  or  closed  receptacles,  to  kill  insects 
infesting  their  contents,  one  drachm  should  be  counted  for  each 
cubic  foot  of  space,  and  a  drachm  may  be  roughly  measured  as  a 
teaspoonful.  It  may  be  placed  in  an  open  vessel  on  top  of  the 
grain  or  other  material,  as  the  vapor,  being  heavier  than  the  air, 
will  descend  to  the  bottom.  It  is  also  useful  in  many  cases 
against  plant-lice,  and  the  range  of  the  material  has  been  already 
given  in  the  various  cases  for  which  it  is  recommended.  It  is 
exceedingly  inflammable  and  explosive,  and  in  no  building  where 
the  material  is  used  should  a  light  be  allowed  or  a  fire  of  any 
kind.  Lighted  pipes  or  cigars  must  be  avoided,  and  even  a 
spark  may  cause  an  explosion.  With  ordinary  precautions,  how- 
ever, the  material  is  a  useful  one,  since  entire  buildings  can  be 
treated  at  once. 

Hydrocyanic  acid  gas  is  another  vapor  exceedingly  destructive 
to  all  life,  but  much  more  fatal  to  animals  than  to  plants.  It  may 
be  used  for  fumigating  nursery  stock  or  for  destroying  scale  and 
other  insects  on  trees.  The  vapor  is  produced  as  follows  :  in  a 
glazed  earthenware  vessel  place  in  the  proportion  of  three  fluid 
ounces  of  water  and  one  ounce  of  ordinary  sulphuric  acid  ;  then 
add  one  ounce  of  fused  potassium  cyanide  of  ninety-nine  per  cent, 
strength.  This  will  generate  a  very  light  and  extremely  poison- 
ous gas  which  is  fatal  to  animal  life  of  all  kinds.  The  quantity 
above  given  suffices  for  one  hundred  and  fifty  cubic  feet,  and  for 
a  larger  or  smaller  space  a  proportionate  amount  should  be  used. 
Trees  to  be  treated  with  this  gas  must  be  covered  by  a  tight  tent 
of  some  kind,  and  for  this  purpose  an  eight-ounce  duck,  soaked 
with  boiled  linseed  oil,  may  be  used.  Where  shrubs  or  small 
trees  are  to  be  fumigated,  a  covered  frame  may  be  used  and 
placed  over  the  plants  by  hand  ;  but  where  large  trees  require 
attention,  it  will  be  necessary  to  have  machinery  mounted  on 
wagons.  In  the  chapter  on  insecticide  machinery,  one  of  these 
tents  will  be  found  figured.  This  hydrocyanic  acid  gas  seems  to 
be  less  fatal  to  plants  and  more  effective  against  insects  at  night 
and  in  cool  weather,  and  treatment  at  such  periods  is  recom- 
mended ;  or  the  tent  may  be  painted  black.  It  should  never  be 
used  in  hot  weather  during  the  middle  of  the  day.  This  is 
another  case  where  an  insecticide  seems  to  be  more  effective  on 
the  Pacific  coast  than  in  the  East ;  but  it  has  not  been  sufficiently 


452  AN  ECONOMIC  EiVTOMOLOGY. 

tested  in  the  Atlantic  States  to  make  it  possible  to  either  encour- 
age or  discourage  its  use.  It  has  the  advantage  of  being  very- 
thorough  where  it  is  at  all  effective,  but  the  outfit  required  for 
large  trees  is  expensive. 

Sulphur  is  an  insecticide  of  comparatively  limited  range,  but  it 
seems  in  some  cases  to  prevent  injury  and  has  almost  a  specific 
effect  upon  many  of  the  mites  which  become  troublesome  in  hot- 
houses. It  is  sometimes  applied  by  dusting  the  flour  of  sulphur 
directly  upon  the  plants,  but  is  more  usually  applied  in  a  watery 
mixture.  Many  nurserymen  place  a  considerable  quantity  of 
crushed  or  powdered  sulphur  in  a  barrel  and  fill  it  with  water, 
stirring  at  intervals,  and  allowing  it  to  remain  for  days  or  even 
weeks,  using  from  it  and  adding  water  as  necessary.  By  boiling 
with  lime,  the  sulphur  can  be  entirely  dissolved,  and  a  more 
effective  mixture  will  be  obtained.  In  orange  groves  sulphur  is 
largely  used  against  the  rust  mite,  and  is  effective  by  simply 
spreading  it  over  the  surface  of  the  ground.  It  seems  to  cause  a 
slow  fumigation  of  the  trees  sufficient  to  destroy  the  mites.  Cu- 
riously enough,  this  remedy  seems  less  satisfactory  on  the 
Pacific  coast  than  it  has  been  found  in  the  East. 

Gas-tar  is  sometimes  recommended  for  certain  purposes  as  an 
insecticide,  and  more  frequently  as  a  repellent ;  but  it  is  rarely 
of  any  practical  value.  It  never  serves  to  repel  from  any  sur- 
face which  it  does  not  cover  and  mechanically  protect, — -that  is  to 
say,  its  odor  will  not  prevent  insects  from  attacking  plants  near 
it.  It  has  been  suggested  that  by  placing  it  around  the  base  of 
plants  like  squashes,  the  borers  can  be  prevented  from  entering 
the  plant ;  but  the  moths  will  simply  lay  their  eggs  a  little  way 
from  it,  and  the  caterpillars,  when  hatched,  bore  into  the  stem  at 
any  point  not  actually  touched  by  the  tar  itself  Another 
method  that  has  been  recommended  is  to  put  a  quantity  of  tar 
into  a  barrel  and  fill  up  with  water  ;  then  stir  occasionally  until 
the  water  becomes  impregnated  with  whatever  it  can  dissolve 
out.  This,  it  has  been  said,  is  useful  against  plant-lice  ;  but  I 
have  never  found  any  beneficial  effects  from  it,  and  deem  it  of 
altogether  too  uncertain  a  value  to  be  recommended. 

Naphthaline  has  been  used  as  an  insecticide,  but  is  of  compara- 
tively little  value  in  the  field,  where  its  cost  will  prevent  its  gen- 
eral use.     The  vapor  given  off  by  it  is  offensive  and  even  poi- 


IXSECTICWES,    PREVENTIVES,   AND    MACHINERY.      453 

sonous  to  many  kinds  of  insects,  so  it  may  be  used  to  protect 
against  their  attacks  in  stored  products.  It  has  been  said  that  a 
sprinkhng  of  naphthahnc  crystals  on  the  surface  of  grain  recep- 
tacles will  keep  out  all  sorts  of  pests,  and  no  doubt  there  is 
more  or  less  basis  for  this  claim.  Naphthaline  is  used  to  keep 
museum  pests  out  of  boxes  and  cases  containing  specimens. 
Packed  with  clothing,  woollens,  or  fabrics  of  any  kind  in  a  toler- 
ably tight  box  or  closet,  it  will  protect  them  from  the  attacks  of 
' '  moths. ' ' 

Quassia,  in  the  form  of  a  decoction,  has  been  recommended 
for  insects  of  various  kinds,  noticeably  plant-lice  ;  but,  in  my  own 
experience,  the  results  obtained  have  been  so  unsatisfactory  that  it 
would  hardly  pay  to  recommend  it,  when  the  soaps  are  so  much 
more  effective  as  well  as  less  expensive. 

It  remains  to  say  a  few  words  on  the  subject  of  patented  insect- 
icides, or  mixtures  sold  under  fancy  names.  As  a  general  rule, 
such  should  be  avoided.  Many  of  them  are  more  or  less  merito- 
rious, but  in  most  instances  they  are  paid  for  altogether  too 
highly.  In  some  cases  the  name  has  covered  a  mere  mixture  of 
Paris  green  and  land  plaster,  charged  for  at  many  times  its  true 
value,  and  then  advertised,  besides,  as  being  harmless.  The 
range  of  the  insecticides  already  mentioned  will  serve  almost 
every  purpose  required  by  the  farmer,  and  before  using  any  pat- 
ented preparation,  he  should  make  an  effort  to  ascertain  just 
what  material  he  is  applying  to  his  plants.  It  is  also  advisable  to 
warn  against  the  plausible  schemes  for  preventing  injury  to  trees 
and  other  plants  by  "  inoculation," — that  is  to  say,  placing 
some  substance  into  the  body  of  the  tree,  with  the  idea  that  it 
will  be  carried  into  the  circulation  to  repel  insects  that  might  be 
tempted  to  feed  upon  the  foliage.  All  such  preparations  hereto- 
fore used  have  been  frauds,  and  no  benefit  has  ever  resulted  from 
any  of  them.  In  the  same  category  belong  those  mixtures  into 
which  seed  potatoes  or  other  seeds  are  to  be  dipped  or  rolled  to 
prevent  the  attacks  of  potato-beetles  or  other  leaf-feeding  insects. 


454  AN  ECONOMIC   ENTOMOLOGY. 


CHAPTER    V. 

MACHINERY. 

Having  determined  the  character  of  an  injurious  insect  and 
the  remedy  to  be  applied,  it  remains  to  decide  the  method  in 
which  the  appHcation  is  to  be  made, — i.e.,  whether  the  poison  is 
to  be  used  dry  or  in  a  watery  mixture  ;  and  this  necessitates 
some  information  concerning  pumps,  nozzles,  bellows,  and  the 
like.  There  is  no  better  indication  of  the  progress  of  economic 
entomology  than  the  large  number  of  firms  now  engaged  in 
manufacturing  and  supplying  machinery  for  the  application  of 
insecticides.  Every  agricultural  journal  contains  advertisements 
of  such  firms,  and  almost  all  of  them  issue  illustrated  catalogues 
describing  their  wares.  It  will  be  for  the  farmer,  with  the  knowl- 
edge of  his  own  requirements  and  necessities,  to  decide  just  what 
kind  of  an  outfit  he  needs,  and  all  that  can  be  done  here  is  to 
give  a  few  suggestions  as  to  the  principles  underlying  the  appli- 
cation of  insecticides. 

Whether  we  apply  dry  powders  or  watery  mixtures,  the  prime 
essential  in  all  cases  is  thoroughness.  Where  poisons  are  to 
kill  by  contact,  it  is  easily  realized  that  contact  is  essential, — that 
is  to  say,  that  the  insect  must  be  actually  touched  by  the  poison 
to  be  at  all  effective.  I  have  shown  that  such  poisons  kill  in  most 
instances  by  either  entering  the  body  through  the  spiracles  or 
clogging  them  ;  hence,  also,  the  entire  insect  must  be  covered 
by  the  poison,  if  it  is  to  be  entirely  effective.  Where  stomach 
poisons  are  to  be  used,  it  is  equally  essential  that  all  parts  of  the 
plant  be  covered,  so  that,  no  matter  how  little  the  insect  eats,  it 
will  yet  obtain  a  poisonous  dose.  The  amount  of  actual  poison 
required  to  kill  most  insects  is  very  small,  but  in  order  that  they 
may  obtain  even  this  small  quantity,  the  entire  food-plant  must 
be  covered.  The  essential  feature  of  a  perfect  machine  for  ap- 
plying insecticides  is,  therefore,  that  it  shall  quickly,  thor- 
oughly, and  economically  distribute  whatever  poison  is  used. 
In  some  cases  the  application  of  dry  poisons  is  desirable,  though 
the  method  is  often  a  wasteful  one,  besides   involving  a  greater 


INSECTICIDES,   PREVENTIVES,   AND    MACHINERY.      455 

or  less  amount  of  expense  for  the  diluting  substance.  Yet,  when 
such  an  application  is  advantageous,  we  find  that  there  are  very 
few  machines  on  the  market  for  making  it.  The  most  elaborate 
and  practical  machine  is  the  Leggett  "  Champion  Powder-Gun," 
which,  by  means  of  a  fan-blower,  distributes  dry  insecticides  in  a 
very  fine  dust.  With  this  machine,  pure  Paris  green  or  London 
purple  can  be  applied  so  thoroughly  that  all  parts  of  a  plant 
may  be  covered  ;  and  as  extension  tubes  and  bent  tips  are  fur- 
nished, small  trees  or  high  bushes  can  be  conveniently  reached. 
This  is,  I  think,  the  best  of  the  machines  on  the  market  for  dis- 
tributing dry  powders  of  all  kinds.  It  is  manufactured  by  Leg- 
gett &  Brother,  New  York  City,  at  a  price  of  about  $7.50. 

There  is  a  variety  of  smaller  bellows  made  by  other  manu- 
facturers, but  they  are  scarcely  practical  for  use  on  a  large  scale. 
Those  sent  out  from  the  Hammond  Slug-Shot  Works  are  as 
satisfactory  and  as  low  in  price  as  any,  and  the  ' '  Woodason 
Bellows,"  sold  by  most  seedsmen  and  dealers  in  insecticides,  are 
also  effective  on  a  small  scale.  In  this  short  list  the  machinery 
for  the  application  of  dry  powders  is  practically  exhausted.  There 
have  been  many  other  machines  produced  and  patented,  and  in 
the  reports  of  the  United  States  Entomological  Commission  there 
are  numerous  cuts  and  figures  of  expensive  dusting  arrangements, 
none  of  which  are  in  use  at  the  present  day.  On  the  other 
hand,  the  tendency  is  all  towards  simplicity.  A  great  many 
farmers  who  apply  dry  powders  use  the  most  rudimentary  kinds 
of  dusters, — perforated  tin  pans  or  the  like.  The  cotton  growers 
of  the  South  have  originated  for  their  purpose  a  simple  and  very 
effective  method  of  applying  dry  Paris  green,  and  perhaps  this 
will  prove  practical  in  other  cases  as  well.  It  consists  of  a  flex- 
ible, tough  pole,  to  each  end  of  which  a  coarse  cloth  sack,  filled 
with  pure  Paris  green  or  London  purple,  is  tied.  The  stick  is 
rested  across  the  back  of  a  mule,  which  is  slowly  driven  between 
the  rows  of  cotton,  and  the  rider,  striking  continually  with  a 
short  stick  on  the  flexible  pole  bearing  the  bags,  jars  them  suffi- 
ciently to  dust  out  a  very  fine  powdering  of  the  poison.  Practi- 
cally, this  is  the  most  satisfactory  method  of  applying  the  arse- 
nites  on  cotton-plants  that  has  been  discovered,  and  it  is  now  in 
almost  universal  use  where  poisons  are  applied  against  the  cotton- 
worm.     The  method  is  extremely  simple,  and  modifications  of  it 


456  AN  ECONOMIC  ENTOMOLOGY. 

adapted  to  his  special  use  will  occur  to  any  intelligent  farmer. 
Applied  through  a  sack,  the  dusting  is  exceedingly  fine,  while  it  is 
at  the  same  time  thorough,  at  least  so  far  as  the  upper  side  of  the 
leaves  is  concerned. 

It  is  in  spraying  machinery  that  the  greatest  advance  has  been 
made,  and  for  a  good  spraying  outfit  there  are  two  essentials, — a 
pump  and  a  nozzle.  The  tank  containing  the  spraying  mixture 
may  be  almost  anything, — a  barrel,  a  tub,  a  box  wagon,  an  elab- 
orate tank  cart,  or  even  a  pail.  What  his  receptacle  shall  be, 
each  farmer  may  decide  for  himself.  The  pump  may  also  be  of 
any  type  or  pattern,  provided  that  at  least  the  working  parts  are 
of  brass,  because  otherwise  the  corrosive  poisons  are  apt  to  destroy 
it.  For  orchard  work,  or  where  large  trees  are  to  be  sprayed, 
the  pump  should  give  a  pressure  of  one  hundred  pounds  or  more, 
without  requiring  too  much  exertion.  It  should  be  double-acting 
to  give  a  continuous  stream,  and  should  have  an  air-chamber  of 
good  size.  The  piston,  or  plunger,  should  not  have  too  great  a 
diameter,  because  the  greater  the  diameter  the  greater  the  amount 
of  force  required  to  obtain  a  desired  pressure.  It  must  be  re- 
membered that  in  ordinary  spraying  operations  the  object  is  not 
to  throw  the  greatest  possible  amount  of  water  in  the  least  pos- 
sible time,  but  to  obtain  the  greatest  amount  of  pressure  with  the 
least  expenditure  of  force.  Force  is  to  be  looked  for  rather  than 
quantity  of  discharge.  There  are  many  pumps  upon  the  market 
fulfilling  all  the  conditions  above  enumerated,  and  at  various 
prices. 

Having  selected  the  pump  and  mounted  it  upon  any  sort  of 
tank,  the  next  question  is  as  to  the  nozzle  to  be  used.  What  we 
want  is  the  finest  possible  spray  and  the  greatest  possible  amount 
of  force,  and  these  two  requirements  are  more  or  less  antagonistic. 
A  very  fine  spray  cannot  be  sent  a  great  distance,  and  a  jet 
capable  of  being  sent  into  the  top  of  a  high  tree  is  a  wasteful 
method  of  application.  There  are,  therefore,  several  types  of 
nozzles  adapted  for  somewhat  different  classes  of  work.  By  all 
odds  the  best,  and  the  one  having  the  greatest  range  of  useful- 
ness, is  the  Vermorel  modification  of  the  "cyclone"  or  eddy- 
chamber  nozzle.  This  consists,  essentially,  of  a  circular  chamber 
into  which  the  water  enters  from  one  side  under  pressure,  receiv- 
ing thus  a  rotary  motion.     The  point  of  exit  is  a  single  hole  in 


Fig.  473. 


Our  coniiiioii  liumhlc-bees.— n,  Xylncnpa  vir_s:inica  ;  h,  Rombus  ferviihn  ;  r,  B.  consiniilis ;  d,  B. 
virginicus  ;  r,  B.  antrricanoyum  (queen)  ;  /',  B .  fmiidiis :  .?-,  A",  amrn'canoruiii  (worker),  to  show 
pollen  mass  on  hind  tibia;  h,  /'.  vagans ;  i,  Apalltus  rlatus.  All  somewhat  nH>re  than  natural 
size. 


INSECTICIDES,   PREVENTIVES,   AND    MACHINERY. 


457 


the  centre  of  a  flat  cap  over  the  chamber.  The  water  emerging 
from  this  opening  under  high  pressure  has  a  whiding  motion 
which  produces  a  cone-shaped  spray  of  exceeding  fineness,  de- 
pending upon  the  amount  of  pressure  and  the  size  of  the  opening. 
With  a  good  pressure  and  an  opening  one-sixteenth  of  an  inch  in 
diameter,  a  fine  mist-like  spray  can  be  sent  a  distance  of  ten  feet, 
and  this  fulfils  as  nearly  as  possible  the  requirements  of  an  ideal 
spray.  In  order  that  it  may  reach  the  tops  of  ordinary  orchard 
trees,  it  is  necessary  that  the  nozzle  should  be  elevated,  and  a  va- 


FiG.  474. 


V\^V.i.i!',VA'.^/V 


Vermorel  nozzle  ami  a  section  to  show  the  working  parts. 

riety  of  means  are  adopted  to  attain  that  end.  In  some  cases, 
where  extensive  orchards  of  large  trees  are  treated,  the  spraying 
is  done  from  a  tank  cart,  and  sometimes  from  a  little  scaffolding 
built  on  it.  More  frequently,  on  moderate-sized  trees,  the  hose 
is  tied  to  a  bamboo  pole  from  ten  to  fifteen  feet  in  length,  and 
with  this  all  such  trees  are  easily  reached.  Instead  of  a  bamboo 
pole  with  the  hose  attached,  some  farmers  use  a  gas-pipe  of 
proper  diameter,  to  the  end  of  which  the  nozzle  is  screwed. 
This  is  somewhat  lighter,  and  the  slender  pipe  is  more  easily 
managed.  But  all  these  are  details  which  the  agriculturist  can 
arrange  for  himself.  A  surprising  amount  of  spray  can  be  ob- 
tained from  a  nozzle  of  this  kind  with  a  very  small  actual  expen- 
diture of  liquid  ;  but  where  a  great  deal  of  spraying  is  done,  two 
or  three  nozzles  grouped  at  the  end  of  a  larger  discharge  pipe  are 
sometimes  used.  The  nozzles  are  so  fixed  that  the  spray  is  sent 
in  all  directions,  and  a  very  large  area  is  covered  by  the  poison 


458 


AN  ECONOMIC  ENTOMOLOGY. 


in  a  very  short  time.  A  moderate-sized  tree  can  be  sprayed  with 
a  group  of  Vermorel  nozzles  in  from  one  to  three  minutes.  A 
good  pump  will  easily  supply  two  lines  of  hose,  and  most  of 
those  now  made  for  orchard  spraying  are  supplied  with  two  dis- 
charge openings.  A  three-quarter  hose  is  all  that  is  necessary, 
even  when  a  compound  nozzle  is  used.  The  Vermorel  nozzle 
is  supplied  with  a  ' '  degorger, ' '  or  apparatus  for  cleaning  out 
the  spray  opening  in  case  it  becomes  clogged  ;  but  it  is  not 
easily  clogged,  and  is,  in  fact,  one  of  the  most  satisfactory  from 
that  stand-point.  With  a  screen  at  the  bottom  of  the  suction 
pipe  the  meshes  of  which  are  not  larger  in  diameter  than  the  dis- 
charge opening  in  the  nozzle,  clogging  should  be  practically  im- 
possible. 

Fig.  475. 


The  Nixon  nozzle. — i,  complete  ;  2,  3,  the  two  parts,  separated. 


The  Nixon  nozzle  is  a  satisfactory  bit  of  apparatus,  working 
on  an  entirely  different  principle  from  the  cyclone.  Here  we 
have  a  barrel-shaped  cylinder  of  varying  length,  at  the  base  of 
which  the  water  enters  through  a  small  opening  in  a  solid  jet,  di- 
rected against  a  wire  screen  at  the  tip  of  the  cylinder.  With  a 
good  force  behind  it,  a  fine  spray  is  sent  from  such  a  nozzle  from 


INSECTICIDES,   PREVENTIVES,   AND    MACHINERY.      459 


ten  to  fifteen  foct.  This  nozzle  has  proved  very  satisfactory  in 
orchard  work,  but  has  the  disadvantage  of  clogging  very  much 
more  readily  than  the  cyclone,  and  of  not  clearing  easily  when 
it  does  clog.  With  a  proper  netting  at  the  end  of  the  suction 
pipe,  the  tendency  to  clog  can  be  reduced  to  a  minimum,  and 
with  a  little  practice  in  actual  field  work,  the  nozzle  has  proved 
satisfactory . 

The  McGowen  nozzle  is  of  yet  a  different  type,  and  throws  a 
fan-shaped  spray  the  quantity  of  which  can 
be  varied  by  adjusting  a  spring  which  regu- 
lates the  size  of  the  opening.  The  nozzle 
has  the  advantage  of  being  self-clearing, — 
that  is  to  say,  any  obstruction  which  may 
lodge  at  the  opening  creates  a  pressure 
sufficient  to  overcome  the  strength  of  the 
spring,  and  the  vent  broadens  sufficiently 
to  allow  the  escape  of  anything  that  can 
get  into  the  barrel  of  the  nozzle.  As  soon 
as  the  obstruction  is  removed,  the  spring 
restores  the  opening  as  originally  set.  The 
peculiarities  of  this  nozzle  are  that  the  spray 
can  be  thrown  a  much  greater  distance  than 
with  any  of  the  types  previously  mentioned, 
and  that  the  amount  of  liquid  to  be  dis- 
charged can  be  regulated.  It  has  certain 
advantages,  therefore,  in  an  orchard  where 
large  trees  are  to  be  treated,  but  it  does 
not  throw  as  fine  a  spray  over  so  great  a 
surface  as  the  Vermorel. 

For  spraying  very  large  trees  many 
growers  have  found  a  cheap  graduating 
nozzle  effecti\e.  This  is  a  cylinder  with 
a  large  flared  opening,  through  which  a 
conical  pin  may  be  forced,  even  to  its  com- 
plete closure.  When  the  pin  is  completely 
retracted,  which  is  done  by  turning  the 
barrel  of  the  nozzle,  a  solid  jet  is  thrown, 
and  any  intermediate  grade  between  this  and  a  tolerably  fine 
spray  may  be  readily  obtained.     For  spraying  shade-trees  nothing 


The  McGoweii  nozzle 
and  a  section  through  its 
tip  to  show  working  parts. 


460 


AN  ECONOMIC   ENTOMOLOGY. 


Fig.  477. 


is  more  satisfactory  than  this,  because  it  gives  the  greatest  range 
in  distance  and  in  quantity  of  discharge.     Even  if  the  spray  is 

coarser  than  with  the  other  nozzles, 
the  work  is  more  rapid.  Practically, 
it  will  not  be  necessary  to  go  beyond 
the  nozzles  already  described  to  ob- 
tain satisfaction. 

The  Vermorel  modification  of  the 
cyclone  nozzle  is  manufactured  by 
almost  all  makers  of  insecticide 
machinery,  and  can  be  obtained 
anywhere.  The  graduating  nozzle 
may  be  purchased  in  almost  any 
hardware  store,  or  wherever  lawn 
sprinklers  and  garden  hose  supplies 
are  sold.  The  Nixon  nozzle  is 
patented,  and  obtainable  from  the 
Nixon  Nozzle  and  Machine  Com- 
pany, Dayton,  Ohio,  or  from  their 
agents.  The  McGowen  nozzle  is 
also  patented,  and  obtained  only 
from  J.J.  McGowen,  Ithaca,  New  York.  There  are  many  other 
nozzles  on  the  market,  all  of  which  have  certain  advantages, 
from  which  the  farmer  must  himself  select  those  most  useful  to 
him.  So  there  are  special  nozzles  for  certain  purposes,  as  that 
for  spraying  the  lime,  salt,  and  sulphur  mixture  used  on  the 
Pacific  coast.  All  these  are  advertised  by  dealers  in  spraying 
machinery,  so  that  the  intending  purchaser  can  secure  full  in- 
formation. 

For  spraying  certain  field  crops  on  a  large  scale — e.g.,  pota- 
toes—there  is  a  tendency  to  use  geared  machines, — that  is  to  say, 
tanks  mounted  upon  a  cart,  and  the  pump  geared  to  the  axle,  so 
that  in  simply  driving  through  the  field  it  will  be  operated.  Then, 
by  means  of  an  extension  rod  fitted  with  nozzles,  from  four  to 
six  rows  of  potatoes  or  other  plants  can  be  sprayed  at  one  time. 
Several  manufacturers  make  machines  of  this  character,  and  a 
great  many  of  them  are  in  use,  giving  satisfaction,  as  a  rule. 
They  have  the  advantage  of  covering  a  great  area  in  a  very  short 
time,  and  reducing  the  cost  of  spraying  to  a  minimum,  doing  the 


A  graduating  nozzle. 


INSECTICIDES,   PREVENTIVES,   AND    MACHINERY.      461 

work  evenly  and  with  little  chance  of  missing.  Where  a  large 
acreage  of  potatoes  is  grown,  one  of  these  machines  is  almost  in- 
dispensable, and  with  it  the  potato-beetle  can  be  kept  in  check 
very  readily.  Of  course  these  machines  may  also  be  used  for 
applying  fungicides  on  the  same  plants.  Geared  machines  should 
never  be  used  in  spraying  orchards  ;  or,  if  they  are,  the  gearing 
should  be  thrown  off  and  the  pump  operated  by  hand.  It  is 
practically  impossible  to  spray  orchard  trees  thoroughly  by 
simply  driving  between  the  rows  and  directing  the  spray  from  the 
wagon  to  the  trees  as  they  are  passed.  If  this  is  done,  slipshod 
work  is  apt  to  result  which  will  not  be  effective,  so  that  both 
labor  and  money  will  be  wasted  and  the  spraying  might  as  well 
be  omitted. 

Of  a  somewhat  distinctive  type  is  the  Bean  spray  pump,  which 
forms  a  spray  by  air-pressure,  and  is,  indeed,  practically  an 
atomizer.  It  is  somewhat  complicated,  and  has  not  found  favor 
in  the  East,  though  considered  a  satisfactory  machine  on  the 
Pacific  coast.  It  is  an  apparatus  not  likely  to  clog,  and  the  spray 
produced  by  it  leaves  little  to  be  desired.  I  have  not  seen  it  in 
actual  service,  hence  cannot  say  how  well  founded  is  the  charge 
of  difficulty  of  manipulation. 

' '  Knapsack  pumps' '  have  come  into  very  general  use  of  recent 
years,  and  quite  a  variety  are  now  manufactured, — all  built  upon 
one  general  plan.  There  is  a  copper  tank,  holding  usually  in 
the  neighborhood  of  five  gallons,  and  a  double-acting  pump  con- 
cealed within  the  tank  itself,  and  operated  by  a  lever  that  passes 
either  under  the  left  arm  or  over  the  left  shoulder.  These  knap- 
sack pumps  may  be  used  for  a  very  great  range  of  work.  As  a 
rule,  they  have  a  short  discharge  hose  and  a  brass  rod  or  "  lance" 
terminating  in  a  Vermorel  nozzle.  The  lance  varies  in  length, 
but  its  extreme  is  about  thirty-six  inches,  so  that  low  plants  may 
be  easily  reached  while  the  worker  is  standing  upright.  In  the 
apparatus  furnished  by  Boekel  &  Co.,  of  Philadelphia,  the  nozzle 
is  adjustable  in  such  a  way  that  the  spray  may  be  sent  in  any 
direction.  If  the  under  side  of  low  plants  is  to  be  reached,  the 
nozzle  is  simply  set  so  as  to  spray  upward,  and  in  fact  it  can  be 
adjusted  so  as  to  do  almost  any  kind  of  work  required  in  the 
field  and  vineyard.  For  the  grower  of  small  fruits,  including 
grapes,  a  knapsack   pump  is  almost  indispensable.     Bush  fruits 


^62  AN   ECONOMIC  ENTOMOLOGY. 

like  currants,  gooseberries,  blackberries,  and  raspberries  can  be 
most  satisfactorily  reached  by  a  machine  of  this  kind,  because  it 
can  be  easily  operated  wherever  the  operator  himself  can  go. 

There  are  many  good,  simple  pumps  now  on  sale,  some  of  them 
single-acting, — little  more  than  a  syringe,  in  fact ;  others  double- 
acting,  and  throwing  a  fairly  good  jet  for  considerable  distances. 
These  are  usually  termed  "bucket  pumps,"  and  are  satisfactory 
in  some  cases,  but  are  rarely  advisable  where  work  is  to  be  done 
on  anything  like  a  large  scale.  A  good  bucket  pump  is  very 
desirable,  however,  where  kerosene  emulsion  is  to  be  made,  and 
it  will  easily  pay  for  itself,  by  facilitating  the  preparation  of  this 
material,  if  it  is  to  be  used  in  quantity.  With  a  good  bucket 
pump  three  gallons  of  emulsion  may  be  made  in  five  minutes 
after  the  soapsuds  have  been  heated  to  the  boiling-point. 

This  is  hardly  the  place  to  recommend  makers  of  insecticide 
machinery  or  machines  of  special  types.  The  farmer,  before 
purchasing,  should  look  through  the  advertisements  in  his  farm 
papers,  and  write  for  catalogues  to  those  advertising  spraying 
machines.  From  these  catalogues  he  should  be  able  to  select 
a  proper  outfit  for  his  special  purpose,  keeping  in  mind  the 
recommendations  that  have  been  made  in  this  chapter.  There 
is,  however,  one  warning  that  must  be  given  :  the  cheapest  outfit 
is  not  always  the  one  that  costs  the  least  money  !  Durability 
should  be  looked  to  as  well  as  effectiveness  and  simplicity  of 
structure,  so  that  if  there  is  anything  out  of  order  it  can  be 
readily  repaired  by  the  farmer  himself.  Strength  is  desirable  in 
all  the  parts,  and  the  structure  of  the  valves  and  the  character  of 
the  packing  should  be  looked  to.  Cheap  pumps,  as  a  rule,  have 
unreliable  valves  and  ordinary  cotton  packing.  The  best  pumps 
have  brass  valves  and  metal  packing,  so  that,  except  in  cases  of 
accident  or  extreme  carelessness,  repacking  is  not  required  for 
years,  if  at  all.  In  fact,  a  pump  should  be  selected  just  as  care- 
fully as  any  other  piece  of  machinery,  and  when  a  proper  outfit 
is  purchased,  it  should  be  studied  until  it  is  thoroughly  under- 
stood. It  will  then  be  possible  to  use  it  with  satisfaction,  and  the 
results  are  apt  to  be  good. 

There  is  now  upon  the  market  a  machine  to  avoid  making 
an  emulsion  where  kerosene  is  to  be  used,  by  providing  for  a 
mechanical  mixture  of  kerosene  and  water  in  the  proper  propor- 


INSECTICIDES,    PREVENTIVES,   AND    MACHINERY.      463 

tions  in  the  act  of  spraying-.  At  the  present  writing  this  machine 
is  not  sufficiently  perfected  to  warrant  me  in  recommending  it, 
but  no  doubt  practical  machines  will  be  constructed,  in  the  near 
future,  carrying  kerosene  in  one  tank  and  water  in  another,  with 
a  pump  so  arranged  that  the  materials  will  combine  in  a  mechani- 
cal mixture  that  can  be  satisfactorily  applied  to  plants. 

Fig.  479. 


An  "  emulsion"  knapsack  sprayer  for  combining  kerosene  and  water. 


For  applying  insecticides  underground,  which  is  sometimes 
desirable  in  using  bisulphide  of  carbon  against  the  cabbage-root- 
maggot  and  other  subterranean  species,  there  is  only  one  satis- 
factory piece  of  machinery, — the  McGowen  injector.  This  is  best 
explained  by  Fig.  481,  illustrating  its  use  on  cabbages.  The  fol- 
lowing directions  may  be  observed,  and  will  at  the  same  time 
indicate  the  method  in  which  the  machine  may  be  used  for  other 
purposes. 

The  method  of  inserting  the  injector  is  shown  in  Fig.  481. 
The  hole  should  always  begin  at  a  distance  of  three  or  four  inches 


Fig.  481. 


Fig.  480. 


Fig.  478. 


f 


Fig  480,  the  McGoNSMi    mp  .  t'ji   in  section,  showing  its  working  parts.     Fig.  481,  illus- 
trating method  ol  using  McGowen  injector.    Fig.  478,  a  knapsack  sprayer. 
464 


INSECTICIDES,   PREVENTIVES,   AND    MACHINERY.      465 

from  the  plant,  and  run  horizontally  downward  to  a  point  a  little 
below  the  roots.  To  accomplish  this  the  injector  must  be  inserted 
at  an  angle,  as  shown  in  the  figure.  Force  it  down  until  the 
point  is  a  little  below  the  roots,  then  let  out  the  charge  of  liquid. 
In  operating  the  injector,  first  pull  the  piston  up  as  far  as  it  will  go. 
This  loads  the  measuring  chamber  between  the  vahes.  Then 
push  down  the  piston  until  it  stops,  and  the  instrument  is  ready 
to  be  pushed  into  the  ground.  Push  it  into  the  ground  as  far  as 
desired.  Hold  it  there  while  you  pull  up  the  piston.  By  this 
operation  you  let  the  charge  out  of  the  lower  chamber  into  the 
ground,  and  at  the  same  time  the  measuring  ciiamber  is  again 
filled.  Hold  the  injector  in  the  ground  a  few  seconds  after  the 
piston  has  been  pulled  up,  in  order  that  all  the  liquid  in  the 
charge  may  have  a  chance  to  run  out.  Then  pull  the  injector 
out  of  the  ground,  and  quickly,  with  the  foot,  fill  the  hole  with 
earth  and  step  on  it  to  pack  it  down.  Press  down  the  piston, 
and  you  are  ready  to  treat  the  next  plant.  Never  push  the 
injector  into  the  ground  unless  the  piston  is  clear  down,  because, 
if  the  lower  end  is  not  thus  closed,  it  will  immediately  fill  with 
soil,  which  is  not  easily  removed.  Study  the  drawings  in  Fig. 
480,  in  connection  with  these  directions,  and  you  will  under- 
stand the  reason  for  each  step.  We  would  advise  that  the  reser- 
voir be  fi«-st  filled  with  water  and  the  injector  operated  above  the 
ground  until  each  step  is  thoroughly  understood.  There  is 
nothing  complicated  about  the  instrument  or  the  way  it  is  to  be 
operated.  It  can  be  easily  taken  apart  and  cleaned,  if  necessary  ; 
the  only  caution  to  be  observed  in  replacing  the  parts  is  to  have 
the  flanges  of  the  leather  in  the  upper  valve  turned  upward. 
The  injector  is  made  by  John  J.  McGowen,  Ithaca,  New  York. 

Under  this  head  we  may  refer  to  the  "hopper-dozers"  which 
have  been  recommended  against  certain  Hemiptera  and  Orthop- 
tera.  These  are  simply  shallow  pans  of  thin  sheet-iron,  of  con- 
venient length  for  the  special  use  intended,  mounted  on  runners 
so  high  as  to  bring  the  bottom  of  the  pan  to  the  top  of  the  vege- 
tation to  be  treated.  The  runners  can  easily  be  made  adjustable  in 
height  by  any  clever  mechanic.  The  front  of  the  pan  is  turned 
up  enough  to  prevent  its  cutting  or  otherwise  injuring  vegetation, 
and  the  sides  are  also  turned  up  at  least  two  inches  and  the  cor- 
ners made  sufficiently  close  to  hold  water,  if  necessary.     Along 


466  AN  ECONOMIC  ENTOMOLOGY. 

the  hinder  edge  is  stretched  a  canvas-covered,  upright  frame,  at 
least  twelve  inches  high,  which  prevents  grasshoppers  from  jump- 
ing over  the  machine.  The  ' '  dozer' '  may  be  drawn  by  man  or 
by  horse-power,  and  when  in  use  the  bottom  is  covered  with  crude 
petroleum,  or  with  water  on  which  is  floated  a  film  of  kerosene. 
The  canvas-covered  frame  is  also  moistened  with  kerosene.  As 
the  apparatus  is  drawn  through  the  fields  the  insects  jump  up 
before,  and  usually,  in  trying  to  leap  over,  fall  into  it.  Even  if 
they  jump    out   again  immediately,   they  are  doomed,   because 

Fig.  482. 


"  Hopper-dozer"  for  man-power. 

once  wet  with  kerosene  they  die  in  a  few  minutes.  These 
machines  are  useful  only  on  comparatively  level  ground,  but  they 
often  destroy  great  numbers  of  injurious  insects  when  properly 
handled. 

Finally,  we  may  say  a  few  words  concerning  fumigating  appa- 
ratus. No  two  outfits  are  quite  alike,  and  the  work  to  be  done 
must  in  every  case  determine  the  character  of  the  machinery. 
The  essentials  are  a  gas-tight  tent,  and  a  means  of  placing  it  over 
the  plants  to  be  fumigated.  The  method  of  producing  the  gas 
is  elsewhere  described.  For  the  tent,  eight-ounce  duck,  saturated 
with  boiled  linseed  oil,  is  recommended,  and  it  should  be  made 
to  close  so  tightly  that  little  gas  can  escape  through  the  lap.  As 
for  the  machinery  to  place  it  over  the  tree,  that  must  be  in  all 
cases  determined  by  the  circumstances  ;  but  Fig.  483  will  give  an 
idea  of  the  way  things  are  done  in  California.  The  outfit  is  an 
expensive  one,  and  will  pay  only  when  an  entire  neighborhood 
can  be  supplied  by  it. 


Fk;.  4S;v 


The  Wullnkill  niiuiLialur. 


INDEX. 


Abdomen,  how  made  up,  26. 
Acanthia  Icctularia,  155. 
Achatodes  zcce,  299. 
Acrididre,  defined,  85. 

life  history,  89. 
Acridium  species,  89. 
Acronycta  americana,  289. 
Actias  luna,  282. 
Aculeata,  defined,  390. 
Adaha  bipuncta,  174. 
Adephaga,  defined,  165. 
AgalHa  sanguinolenta,  147. 
Agaristidre,  264. 
Agricuhural  ants,  398. 
Agrilus  ruficolhs,  186. 

sinuatus,  187. 
Air-sacs  or  bladders,  36. 

-tubes,  extensile,  37. 
Alaus  oculatus,  183. 
Alder-blight,  133. 
Aletia  argillacea,  301. 
Aleyrodes  citri,  122. 
AleyrodidtE,  121. 
Allorhina,  species,  203. 
Alulet,  365. 

Alypia  octo-maculata,  263. 
Ambulatoria,  81. 
American  blight,  133. 
Amm.  solution  of  copper  carbonate,  439. 
Amphicerus  bicaudatus,  195. 
Anabrus  simplex,  97. 
Anal  glands  and  secretions,  30. 
Anasa  tristis,  160. 
Anatis  15-punctata,  174. 
Andrena  species,  411. 
Angoumois  grain  moth,  326. 
Anisopteryx  species,  307. 
Anisota  senatoria,  278. 
Anomala  lucicola,  202. 


Anomis  species,  300. 
Antenn;\;,  function  of,  20. 

general  characters,  19. 
Anthocoridas,  156. 
Anthomyiids,  360. 
Anthonomus  4-gibbus,  232. 

signatus,  231. 
Anthrax,  species  of,  345. 
Anthrenus  scrophularioe,  179. 
Ant-lions,  76. 
Ants,  described,  390. 

and  plant-lice,  127,  394. 
Apanteles  species,  383. 
Aphaniptera,  328. 
Aphelinus  mytilaspidis,  385. 
Aphididse,  123. 
Aphidius  species,  384. 
Aphis-lions,  74. 

mali,  134. 

parasites,  383. 

persicae-niger,  134. 
Aphodius,  198. 
Apis  mellifica,  414. 
Apple,  Anthonomus  on,  232. 

blight-louse,  133. 

case-bearer,  324. 

codling  moth  on,  322. 

flat-head  borer  in,  186. 

leaf-crumpler,  313. 

long-horned  twig-borers,  209. 

-louse,  134. 

-maggot,  366. 

oyster-shell  scale  on,  115. 

round-head  borer  in,  209. 

tree-hoppers  on,  138. 

twig-borer,  195. 

yellow-neck  caterpillar,  275. 
Aquatic  forms,  how  they  breathe,  36. 
Aramigus  fuUeri,  228. 

467 


468 


INDEX. 


Arbor-vitse,  bag-worm  on,  273. 
Arctiidse,  266. 
Argynnis  species,  244. 
Arista  of  flies,  330. 
Armored  scales,  114. 
Army-worm,  294. 
Arsenate  of  lead  and  its  use,  436. 
Arsenic  as  an  insecticide,  437. 
Arsenites  and  their  use,  434,  438. 
Ascalaphus  species,  76. 
Asilidoe,  344. 
Asopia  costalis,  312. 
Asparagus  beetle,  211. 
Aspidiotus  perniciosus,  118. 
Atomaria  species,  177. 
Atropos  species,  69. 
Attacus  species,  279, 
Auditory  sense  of  insects,  43. 
Automeris  io,  283. 

Bag-worms,  273. 
Balancers  of  flies,  327. 
Balaninus  species,  234. 
Bandings  of  printers'  ink,  etc.,  433. 
Bark-beetles,  237. 

-slippers,  207. 
Beak  of  bug  mouth,  16. 
Bean  lady-bird,  175. 

-weevils,  223. 
Bean  spray  pump,  461. 
Bed-bug,  155. 
Beech  blight,  133. 
Bees,  407. 

long-  and  short-tongued,4io. 
Bee-flies,  345. 

-louse,  370. 

-moth,  316. 

mouth,  19. 
Beet-leaf  magots,  365. 
Beetles,  chapter  on,  164. 

classification  of,  165, 
Bell  moths,  319. 
Bellows,  455. 

Belostoma  americana,  150. 
Bembecia  marginata,  260. 
BembecidfE,  403. 
BibionidcC,  340. 
Bichloride  of  mercury,  438. 
Bill-bugs  in  corn,  236. 


Bipectinated  antennae,  21. 
Bisulphide  of  carbon,  450. 

against  hen-lice,  71. 
against  Termites,  67. 
Biting  lice,  described,  70. 
Bittacus,  77. 

Black  beetles,  their  habits,  82. 
Blackberry  cane-borer,  186. 

crown-borer,  260. 

pithy  gall,  378. 

root-borers,  206. 

saw-fly  borer,  375. 
Black  flies,  340. 
Blattidse,  described,  81. 
Blennocampa  pygmsea,  374. 
Blissus  leucopterus,  158. 
Blister  beetles,  225. 
Blood  of  insects,  33. 
Blow-fly,  257. 
Blues  and  coppers,  245. 
Body-louse,  life  history,  105. 
Boll-worm,  303. 
Bombardier  beetles,  168. 
Bombyliidae,  345. 
Bombylius  species,  345. 
Book-lice,  68. 
Borax,  against  roaches,  82. 
Bordeau.x  mixture  and  its  uses,  439. 
Boreal  lady-bird,  175. 
Borers,  remedies  for,  188. 
Boreas,  j^. 
Bostrychus,  193. 
Bots  on  cattle,  352. 
Bot-flies,  351. 
Brachinus,  168. 
Brachystola  magna,  91. 
Braconidae,  382. 
Brain  in  insects,  39. 
Bran  and  Paris  green,  438. 
Braula  cEeca,  370. 
Breast-bone  of  gall-gnats,  336. 
Breathing  of  insects,  33. 
Bristle-tails,  53. 
Bristled  antennee,  22. 
Bruchidag,  223. 
Brush-footed  butterflies,  242. 
Bucket-pumps,  462. 
Buffalo  gnat,  340. 

grasshopper,  91. 


INDEX. 


469 


Buffalo  moth,  179. 

tree-hoppers,  138. 
Bugs,  defined,  100. 
Buhach,  442. 
Bumble-bees,  411. 

life  history,  416. 
Buprestidas,  185. 
Buprestis,  185. 
Butterflies,  chapter  on,  240. 

classified,  241. 

mouth  of,  16. 
By  turns  unicolor,  180. 

Cabbage  butterflies,  246. 

harlequin  bug  on,  162. 

-lice,  134. 

-maggot,  361. 

Plusia,  302. 

thrips,  102. 

-worms,  parasites  on,  385. 
Cacoecia  fervidana,  321. 

rosaceana,  321. 
Caddice-flies.  77. 
Cadelles,  182. 

Caecal  tubes  or  pouches,  30. 
Calandra,  species  of,  237. 
Calliphora  vomitoria,  357. 
Camel  crickets,  97. 
Canker-worms,  307. 
Capsidas,  156. 
Carabidoe,  166. 

Carbolic  acid  and  its  uses,  446. 
Carbon  disulphide  and  its  uses,  450. 
Carnivorous  beetles,  165. 
Carolina  locust,  88. 
Carpenter  ants,  391. 

bees,  412. 
Carpet  beetle,  179. 
Carpocapsa  pomonella,  322. 
Carpophilus  hemipterus,  181. 
Carrion  beetles,  171. 
Cassida  bivittata,  222. 
Cassidae,  222. 
Catch  crops,  use  of,  426. 
Caterpillar  hunters,  168. 
Catocala  species,  306. 
Caustics,  how  they  kill,  39. 
Caustic  potash  and  soda  washes,  450. 
Cecidoniyia  destructor,  336. 


Cecidomyia  leguminicola,  338. 
Cecidomyida;,  336. 
Cecropia  moth,  280. 
Cephalo-thorax,  defined,  34. 
Cephus  pygmceus,  376. 
CerambycidiK,  205. 
Ceraphron  triticum,  388. 
Ceratocampidae,  278. 
Ceratomia  amyntor,  257. 
Ceratopogon  species,  334. 
Ceratopsyllus  serraticeps,  329. 
Ceresa  bubalus,  139. 
Cerci,  defined,  26. 
Cercopidae,  defined,  146. 
Ceroplastes,  112. 
Chretocnema  confinis,  219. 
Chalcidida;,  384. 
Chalcophora,  185. 
Chauliodes  pectinicornis,  72. 
Chauliognathus,  191. 
Chermesinas,  defined,  128. 
Cherry-louse,  134. 
Chestnut  weevils,  234. 
Chicken-fleas,  329. 

-lice,  71. 
Chickens  versus  insects,  426. 
Chilo  species,  317. 
Chilocorus  bivulnerus,  174. 
Chinch-bug,  life  history,  158. 
Chinese  silkworm,  286. 
Chionaspis  furfurus,  119. 
Chironomidce,  333. 
Chitine,  peculiarities  of  14,  38. 
Chortophaga  viridifasciata,  88. 
Chrysalis,  defined,  50. 
Chrysanthemum  fly,  348. 
Chrysididoe,  390. 
Chrysobothris,  186. 
Chrysomelidas,  205,  210. 
Chrysopa,  74. 

Chrysophanus,  species  of,  245. 
Chylific  ventricle,  30. 
Cicada,  defined,  139. 

septendecim,  140. 
Cicindelidse,  166. 
Cigarette  beetle,  193. 
Ciliated  antennae,  22. 
Cimbex  americana,  374. 
Circulation  in  insects,  33. 


47° 


INDEX. 


Citheronia  regalis,  278. 
Classification  in  general,  52. 
Clavate  antennas,  21. 
Clavicornia,  defined,  165. 
Cleanliness,  to  check  insects,  423. 
Clear-wing  moths,  259. 
Cleridae,  192. 
Clerus  apivorus,  192. 
Click-beetles,  182. 
Climbing  cut-worms,  292. 
Clisiocampa  americana,  284. 
Clothes  moths,  324. 
Clothilla.  69. 
Clothing  of  bees,  408. 
Clover  hay-worm,  312. 

leaf-beetle,  229. 

seed-midge,  338. 

stem-borer,  176. 
Coccidse,  defined,  106. 
Coccinella  9-notata,  174. 
Coccinellidae,  172. 
Cochineal  insect,  106. 
Cockchafer,  201. 
Cockscomb  gall  on  elm,  132. 
Cocoon,  described,  50. 
Codling  moth,  322. 
Coleoptera,  defined,  54,  55. 

chapter  on,  164. 

classification  of,  165. 
Colias  philodice,  250. 
Colon,  described,  30. 
Colopha  ulmicola,  132. 
Colorado  potato-beetle,  213. 
Commercial    fertilizers    as    insecticides, 

427. 
Complemental  sexes  of  Termites,  66, 
Complete  metamorphosis,  50. 
Compound  eyes,  42. 
Cone-nosed  grasshoppers,  96, 
Conocephalus,  96. 
Conopidre,  351. 
Conorhinus  sanguisuga,  152. 
Conotrachelus  cratsegi,  234. 

nenuphar,  232. 
Contact  poisons,  how  they  act,  38. 
Cook  emulsion,  443. 
Coppers  and  blues,  245. 
Copris  Carolina,  198. 
Coptocycla  aurichalcea,  223. 


Coreidae,  defined,  160. 
Corimelasnidae,  defined,  163. 
Corn  bill-bugs,  236. 

-root  Diabrotica,  215. 

-root-louse,  134. 

-root  web-worm,  317. 

-worm,  303. 
Cornicles,  defined,  126. 
Corisa,  habits  of,  150. 
Coriscus,  153. 
Corrodentia,  68. 
Corrosive  sublimate,  438. 
Corticaria,  177. 
Corydalus  cornutus,  72. 
Corynetes  rufipes,  193. 
Cossidae,  286. 
Cotalpa  lanigera,  202. 
Cotton  boll-worm,  303. 

r^-bug  on,  157. 

-.stj|liner,  157. 

-worm?,  300. 
Cottony  cushion  scale,  108. 

maple  scale,  no. 
Cow-lice,  how  destroyed,  71. 
Coxa,  defined,  26. 
Coxal  cavity,  defined,  26. 
Crab-louse,  105. 
Crambids,  316. 
Crambus  species,  317. 
Cranberry  fire-worm,  320. 

fruit-worm,  313. 

span-worm,  309. 

Teras,  reflowing  for,  428. 
Crane-flies,  330. 
Cremastogaster  lineolata,  392. 
Crepidodera,  219. 
Crickets,  97. 
Crioceris  asparagi,  211. 

i2-punctatus,  211. 
Crop,  described,  30. 

of  lepidoptera,  31. 
Crop  remnants  should  be  removed,  424, 
Croton  bugs,  82. 
Cruciferous  weeds,  lice  on,  134. 
Cryptophagus,  177. 
Cuckoo-bees,  390. 
Cucumber  caterpillar  borer,  311. 

flea-beetle,  219. 

striped  beetle,  214. 


INDEX. 


471 


Cucujidae,  176. 

Culicidoe,  332. 

Cupram,  use  and  formula,  439. 

Curculio,  defined,  228. 

Currant  borer,  263. 

4-lined  plant  bug  on,  156. 

long-horned  borer  in,  208. 

worm,  372. 
Cursoria,  defined,  81. 
Cuterebera  emasculator,  352. 
Cut-worms,  life  history,  290. 

remedies  for,  293. 
Cyclone  nozzle,  456. 
Cydnidce,  defined,  162. 
Cyllene  pictus,  208. 

robinia;,  208. 
Cymatophora  pampinaria,  309. 
Cynipidoe,  defined,  376. 
Cyrtophyllum  concavum,  94. 

Dagger  moths,  289. 

Danais  archippus,  242. 

Darkling  beetles,  224. 

Dascyllidae,  182. 

Datana  ininistra,  276. 

Day-flies,  59. 

Death-watch,  69. 

Delta  moths,  306. 

Deltoids,  306. 

Dendrolene  and  raupenleim,  431. 

Dermaptera,  79. 

Dermestes  lardarius.  178. 

vulpinus,  178. 
Dermestidae,  178. 
Devil's  darning-needles,  60. 
Diabrotica  longicornis,  215. 

i2-punctata,  215. 

vittata,  214. 
Diapheromera  femorata,  86. 
Diaspinae,  defined,  114. 
Diaspis  rosce,  119. 
Diastrophus  nebulosus,  378. 
Diatroea  saccharalis,  318. 
Dicerca,  185. 

Dictyophorus  reticulatus,  91. 
Digestive  system,  described,  28-30. 
Digger  wasps,  399,  403. 
Diplosis  pyrivora,  339. 

tritici,  338, 


Diptera,  chapter  on,  327. 

defined,  54,  55. 
Diseases  of  insects,  418. 
Dissosteira  Carolina,  85. 

longipennis,  85. 
Dobson,  72. 
Dog-flea,  328. 
Dorsal  surface,  25. 
Dorsum,  is  upper  surface,  25. 
Doryphora  lo-lineata,  213. 
Dragon-flies,  60. 
Drasteria  crassiuscula,  305. 

erechtea,  305. 
Drone-fly,  348. 
Drosophila  species,  367. 
Dryocampa  rubicunda,  279. 
Dry  powders,  how  applied,  4S4, 

how  they  kill,  39. 
Dynastes,  203. 
Dysdercus  suturellus,  157. 
Dytiscidce,  169. 

Ears  of  insects,  43. 
Earwigs,  life  history,  etc.,  79. 
Economic  entomology,  development  of, 

9- 
Ectobia  germanica,  82. 
Edema  albifrons,  277. 
Eggs,  number  laid  by  insects,  45. 

of  mantidas,  84. 

of  roaches,  81. 

stage  described,  48. 
Eight-spotted  forester,  263. 
Elaphidion  species,  207. 
Elateridas,  182. 
Electric-light  bugs,  151. 
Elm,  cockscomb  gall  on,  132. 

leaf-beetle,  217. 

4-horned  sphinx  on,  257, 
Elytra,  164. 
Emasculating  bot,  352. 
Empretia  stimulea,  271. 
Enemies  of  insects,  45. 
Ephemeroptera,  described,  59. 
Ephestia  kiihniella,  315. 
Epidapus  scabei,  335. 
Epicauta  cinerea,  227. 

pennsylvanica,  227. 

vittata,  225. 


472 


INDEX. 


Epidemics  among  insects,  45. 
Epilachne  borealis,  175. 

corrupta,  175. 
Epipharynx,  function  of,  15,  43. 
Epitrix,  219. 
Eriocampa  cerasi,  372. 
Eristalis  tenax,348,  350. 
Erotylidae,  175. 
Erythroneura  vitis,  148. 
Euchromia  ipomaese,  264. 
Eucleidae,  271. 
Eumenes,  nests  of,  404. 
Euphoria  inda,  204. 
Euplexoptera,  79. 
Eupogonius,  209. 
Eurycreon  ran  talis,  311. 
Eyes,  compound,  22. 

of  insects,  41. 

Fall  army-worm,  297. 

plowing,  effect  of,  425. 

web-worm,  266. 
Family,  defined,  52. 
Farm  practice  to  prevent  iasect  attack, 

423- 
Feather-wing  moths,  318. 
Feeding  habits,  how  determined,  14. 
Feelers  are  antennas,  19. 
Femur,  defined,  26. 
Fenesica  tarquinius,  246. 
Fertilizers  as  insecticides,  427. 
Fidia  viticida,  211. 
Filicornia,  defined,  165. 
Filiform  antennae,  21. 
Fire-flies,  described,  190 
Fish-moth,  53,  56. 

-oil  soap,  use  and  formula,  445. 
Flat-head  borers,  185. 
Flax-seed  stage  of  Hessian  fly,  336. 
Flea-beetles,  219. 
Fleas,  described,  328. 
Flesh-flies,  356. 
Flies,  chapter  on,  327. 
Flower-beetles,  192. 

-flies,  347. 
Fly,  experiments  with,  41. 
Foraging  ants,  399. 
Forficulidoe,  defined,  79. 
Formicidce,  391. 


Fossores,  399. 
Four-lined  plant-bug,  156. 
Fowls,  affected  by  lice,  71. 
Frog-hoppers,  146. 
Fruit  bark-beetle,  238. 
Fulgoridae,  defined,  146. 
Fuller's  rose-beetle,  228. 
Fumigating  apparatus,  465. 
Funicle  of  antenna,  22. 
Fungus  diseases  of  insects,  418,  422. 
gnats.  334. 

Galeruca  xanthomelaena,  217. 
Gall-flies,  376. 

-gnats,  336. 

-lice,  described,  132. 
Galls,  ink  from,  378. 
Galleria  melonella,  316. 
Ganglia,  described,  39. 
Garden  web-worm,  311. 
Gas-tar  as  an  insecticide,  452. 
Gasoline  as  an  insecticide,  444. 
Gasirophilus  equi,  351. 
Geared  machines,  460. 
Gelechia  cereallella,  326. 
Geniculate  antennce,  22. 
Genus,  defined,  52. 
Geometridce,  307. 
Geotrypes,  198. 
Gills,  of  aquatic  insects,  37. 
Gizzard,  described,  30. 
Glow-worms,  190. 
Gnats,  334,  340. 
Goat-moths,  286. 
Goldsmith  beetle,  202. 
Gouty  gall  on  blackberry,  186. 
Graduating  nozzle,  459. 
Grain-weevils,  237. 
Grape,  American  Procris  on,  264. 

chafers  on,  202. 

8-spotted  forester  on,  263. 

flea-beetle,  219. 

leaf-hopper,  148. 

phylloxera,  128. 

plume-moth,  318. 

Pyrophila  on,  299. 

-root-worm,  206,  212. 

-slug,  373. 
Grapta  comma,  244. 


nXDEX. 


473 


Grass,  leaf-hoppers  in,  147. 

thrips  on,  102. 
Grasshoppers,  life-history,  etc.,  89. 

long-horned,  93. 

short-horned,  85. 
Green-striped  locust,  88. 
Ground-beetles,  described,  166. 
Grouse  locusts,  life-history,  92. 
Gryllidae,  defined,  97. 
Gryllotalpa,  98. 
Gryllus,  species,  99. 
Gypsy  moth,  270. 
Gyrinidns,  170. 

Hasmatobia  scrrata,  358. 
Hair-streaks,  245. 
Halisidota,  species,  268. 
Halteres,  of  flies,  327. 
Haltica  chalybea,  219. 
Ham-beetle,  193. 
Hammer-head  borers,  185. 
Harlequin  cabbage-bug,  162. 
Harrisina  americana,  264. 
Harvest-flies,  139. 
Haustellate  mouth-structures,  16. 
Hawk-moths,  254. 
Head  and  its  appendages,  14. 

-louse,  103. 
Hearing  of  insects,  43. 
Heart,  described,  32. 
Heliothini,  303. 
Heliothis  armiger,  303. 
Hellebore  and  its  use,  440. 
Hellgrammites,  72. 
Hemerobiidce,  described,  72. 
Hemerobius,  74. 
Hemiptera,  chapter  on,  100. 

defined,  53,  55. 
Hen-lice,  71. 
Hermaphrodites,  46. 
Hesperidae,  254. 
Hessian  fly,  336. 

effect  of  late  planting,  428. 
Heterocera,  241,  254. 
Heteromera,  defined,  165,  224. 
Heteroptera,  defined,  .S3,  100. 

treated,  150. 
Hickory  horned  devil,  278. 

phylloxera  on,  130. 


Hippiscus  discoideus,  88. 
Hippoboscidae,  369. 
Hippodamia,  174. 
Hispidai,  221. 
Histeridae,  180. 
Hive-bee,  414. 
Hog-caterpillars,  257. 

-louse,  104. 
Homoptera,  defined,  53,  100,  106. 
Honey-ants,  396. 

-bee,  414. 

-dew,  126. 

-tubes  of  plant-lice,  126. 
Hop,  Grapta  on,  244. 

-louse,  life  history,  125. 

snout-moth,  306. 
Hopper-dozers,  92,  464. 
Horn-fly,  358. 

-tails,  371,  374. 
Hornets,  406. 
Horse-bot,  351. 

-flies,  342. 
House-fly,  356. 

Household  pests,  56,  82,  155,  356,  396. 
Humming-bird  hawk-moths,  257. 
Hybernia  tiliaria,  308. 
Hydrate  of  lime,  dry,  447. 
Hydrobatidas,  defined,  151. 
Hydrocyanic  acid  gas,  451. 
Hydrophilidas,  170. 
Hymenoptera,  chapter  on,  370. 

defined,  54,  55. 
Hypena  humuli,  306. 
Hyperchiria  io,  283. 
Hyper-parasites,  388. 
Hyphantria  cunea,  266. 
Hypoderma  lineata,  352. 
Hypopharynx,   structure   and   function, 
16,  43- 

Icerya,  Vedalia  against,  421. 

purchasi,  108. 
Ichneumon  flies,  381. 
Ichneumonidce,  381. 
Ileum,  described,  30. 
Indian  Cetonia,  204. 
Incomplete  metamorphosis,  50. 
Injectors,  433. 
Inoculation  of  trees,  453. 


474 


INDEX. 


Insect  powder,  442. 

Insecticides,  chapter  on,  418,  434. 

Insects,  defined,  11,  12,  54. 

Insidious  flower-bugs,  156. 

Introduced  insects,  421. 

Introductory,  9. 

lo  moth,  284. 

Ipomaga,  larvae  on,  264. 

Ips  fasciatus,  181. 

Isabella  moth,  266. 

Isomera,  defined,  165. 

Isoptera,  64. 

Isosoma  species,  386. 

Jassidag,  defined,  147. 
Jigger-fleas.  329. 
Joint-worms,  386. 
Jug-handle  grubs,  254. 
Jumping  plant-lice,  137. 
June-bugs,  200. 

Kainit,  against  root-lice,  131. 
Katydids,  described,  94. 
Kermes,  described,  no. 
Kerosene  as  an  insecticide,  442. 

how  it  kills,  38. 
Knapsack  pumps,  461. 

Labium,  structure  and  function,  16. 
Labrum,  structure  and  function,  15. 
Lace-wing  flies,  their  habits,  etc.,  74. 
Lachnosterna,  201. 
Lady-birds,  described,  172. 
Loetilia  coccidivora,  315. 
Lamellate  attennag,  21. 
Lamellicornia,  defined,  165,  196. 
Lampyridae,  igo. 
Lancets  of  fly  mouth,  18. 
Languriamozardi,  176. 
Lantern-flies,  described,  146. 
Laphria,  species,  344. 
Laphygma  frugiperda,  297. 
Larder-beetles,  178. 
Larridse,  403. 

Larvae  distinguished  from  worms,  11. 
Larval  stage,  48. 
Lasioderma  serricorne,  193. 
Lasius  species,  394. 
Lawns,  ants  on,  395. 


Leaf-beetles,  described,  210. 

-chafers,  199. 

-hoppers,  described,  146. 
life-history,  147. 

-roller  caterpillars,  319. 
Leather-beetle,  178. 
Lebia  grandis,  168. 
Lecanium,  defined,  112. 
Leggett  Champion  Powder-gun,  455, 
Legs,  where  located,  25. 

structure  of,  25. 
Lema  trilineata,  211. 
Leopard-moth,  287. 
Lepidoptera,  chapter  on,  240. 

defined,  54,  55. 
Lettuce,  root-lice  on,  127. 
Leucania  albilinea,  296. 

unipuncta,  294. 
Lice,  biting,  their  habits,  etc.,  70. 

on  domestic  animals,  71,  105. 

sucking,  104. 
Life-history,  defined,  50. 

economic  importance  of,  50. 
Ligyrus  rugiceps,  203. 
Limacodidae,  271. 
Lime  as  an  insecticide,  432,  446. 

as  a  preventive,  432. 

salt,  and  sulphur  wash,  448. 

-tree  moth,  308. 
Limnophilus  rhombicus,  78. 
Litargus,  177. 
Lixus  concavus,  230. 
Locomotion,  organs  of,  25. 
Locust  borer,  287. 

leaf-beetle,  222. 
Locustidae,  defined,  93. 
Locusts  or  cicadas,  140. 
Locusts,  destructive  species,  90. 

remedial  measures,  92. 
London  purple,  analysis  of,  435. 
Long-horned  beetles,  205. 
Loopers,  307. 

Losses  caused  by  insects,  9. 
Louse-flies,  369. 
Lo.xostege  similalis,  311. 
Lubber  grasshoppers,  91. 
Lucanidae,  196. 
Lucanus  species,  197. 
Lucillia  macellaria,  357. 


INDEX. 


475 


Luna-moth,  282. 
Lyctena,  species  of,  245. 
Lycaenidae,  242. 
Lygasida;,  defined,  158. 
LymantriidtC  defined,  268. 

Machinery,  chapter  on,  418,  454. 

Macrobasis  nnicolor,  227. 

Macrodactylus  subspinosus,  199. 

Malachiida;,  igr. 

Mallophagidce,  70. 

Malpighian  tubules,  30. 

Mandibles,  structure  and  function,  15. 

Mandibulate  mouth,  15. 

Mantidae,  described,  83. 

Mantis  religiosa,  84. 

Mantispidae,  76. 

Manure,  favors  insects,  428. 

podurids  breed  in,  57. 
Maple-borer,  208. 

clear-wing  borer,  262. 

scale,  life-history,  no. 
March-files,  340. 
Margaronia  nitidalis,  311. 
Mask  of  dragon-fly  larva,  62. 
May-beetles,  200. 

-flies,  their  habits,  etc.,  59. 
Maxillae,  structure  and  function,  15. 
McGowen  nozzle,  459. 

injector,  463. 
Meadow-grasshoppers,  96. 
Meal-worms,  224. 
Mealy-bugs,  described,  106. 

remedies  for,  108. 
Measuring-worms,  307. 
Mecoptera,  77. 

Mediterranean  flour-moth,  315. 
Megachile  species,  412. 
Megathymus  yuccae,  254. 
Megatoma,  179. 
Megilla,  174. 
Melanophila,  185. 
Melanoplus  atlanis,  90. 

femur- rubrum,  90. 

spretus,  90. 
Melitara  dentata,  313. 

prodenialis,  313. 
Melittia  ceto,  259. 
Meloidae,  225. 


Melon-louse,  /ife  history,  126. 
Melophagus  ovinus,  369. 
Membracidae,  defined,  138. 
Mosothorax,  23. 
Mesograpta  polita,  350. 
Metathorax,  23. 
Metamorphosis,  defined,  48. 
Microcentrum  retinervis,  94. 

laurifolium,  94,  95. 
Microgaster,  383. 
Micro-lepidoptera,  310. 
Micropyle,  defined,  47. 
Midaidae,  344. 
Midges,  334,  336. 
Migration  in  plant-lice,  126. 
Milk-weed  butterfly,  242. 
Mineola  indiginella,  313. 

vaccinii,  313. 
Mole-crickets,  98. 
Monilicornia,  defined,  165. 
Moniliform  antennae,  22. 
Monomorium  pharaonis,  396. 
Monophadnus  rubi,  374. 
Monostegia  rosae,  374. 
Mormon  cricket,  habits  of,  97. 
Mosquitoes,  332. 
Mosquito-hawks,  61. 
Moths,  chapter  on,  240. 
Moulting  of  insects,  48. 
Moults,  number  of,  49. 
Mourning-cloak  butterfly,  244. 
Mouth  of  bees  and  wasps,  19. 

importance  of,  14,  16. 

indicates  remedies,  16. 

of  flies,  18. 

types  of,  14. 
Mud-daubers,  402. 
Multicellular  gall,  378. 
Murgantia  histrionica,  162. 
Muscidae,  353,  356. 
Muscles,  structure  and  character,  28. 
Mushroom-gnat,  334. 
Mutillidae,  400. 
Mycetophilidae,  334. 
Myrmecocystus  melliger,  396. 
Myrmeleonidae,  described,  75. 
Myrmicidae,  396. 
Mytilaspis  pomorum,  115. 
Myzus  cerasi,  134. 


476 


INDEX. 


Nabidae,  defined,  153. 

Nabis  fusca,  154. 

Naphthaline  against  book-lice,  69. 

and  its  uses,  452. 
Natural  checks  to  insect  increase,  418. 
Necrophorus,  171. 
Negro-bug,  163. 
Nematus  ribesii,  372. 
Nervous  centre  in  flies,  41. 

system  of  insects,  39. 
Neuroptera,  defined,  53,  54. 

chapter  on,  58. 

described,  72. 
Neuters  in  ants,  391. 
Newspaper  barriers  against  borers,  431. 
Nisoniades,  species  of,  254. 
Nitidulidae,  181. 
Nits  of  lice,  105. 
Nixon  nozzles,  458. 
Noctuidae,  288. 
Notodontidoe,  275. 
Notolophus  leucostigma,  268. 
Nozzles,  types  of,  456. 
Nut-weevils,  234. 
Nymph,  defined,  49. 
NymphalidfE,  242. 

Oak,  Edema  albifrons  on,  277. 

galls,  377. 

leaf-rollers,  321. 

orange-striped  worm  on,  278. 

pruners,  207. 
Ocelli,  described,  41. 

location  of,  22. 
Ocneria  dispar,  270. 
Odonata,  described,  60. 
Odontota  dorsalis,  222. 
CEcanthus  species,  100. 
Qidemasia  concinna,  277. 
CEdipodinpe,  described,  87. 
OEsophagus,  described,  30, 
CEstridse,  351. 
Qistrus  ovis,  352. 
Olfactory  organs,  described,  44. 
Olfersia,  species,  369. 
Oncideres  species,  210. 
Onion  maggot,  363. 

thrips,  102. 
Ophion  species,  382. 


Orange,  Aleyrodes  on,  122. 

cottony- cushion  scale,  108. 

-dog,  253. 

mealy-bugs  on,  106. 

oyster-shell  scales  on,  116. 

red-bug  on,  157. 

Termite  attack  on,  67. 
Orange-striped  oak-worm,  278. 
Orbicular  spot,  289. 
Orchelimum  species,  96. 
Orcus,  174. 

Orders  of  insects,  52,  54. 
Orgyia  leucostigma,  268. 
Ortalids,  365. 
Orthoptera,  chapter  on,  79. 

defined,  53,  54. 
Orthosoma  brunneum,  206. 
Ovaries,  described,  46. 
Oviduct,  described,  46. 
Oviposition  of  Acridiidag,  89. 

Chrysopa,  74 

dragon-flies,  62. 

field-crickets,  99. 

grasshoppers,  89. 

katydids,  96. 

locusts,  94. 

tree-crickets,  100. 
Ovipositor,  described,  46. 

in  crickets,  97. 

of  parasites,  379. 
Owlet  moths,  288. 
Ox-louse,  104. 
Ox-warble,  352. 

Oxyptilus  periscelidactylus,  318. 
Oyster-shell  bark-lice,  115. 

Pain  in  insects,  40. 
Pale-striped  flea-beetle,  221. 
Paleacrita  species,  308. 
Palm-weevil,  236. 
Palpi,  structure  and  function,  16. 
Pamphila,  species  of,  254. 
Panorpidas,  described,  -]•]. 
Paper-making  wasps,  406. 
Papilio  asterias,  250. 

cresphontes,  253. 

philenor,  251. 

turnus,  252. 
Papilionidae,  246. 


INDEX. 


477 


Papilioninae,  250. 
Parasites  on  plants,  377. 
Parasitic  hymenoptera,  379. 

insects,  chapter  on,  418. 
Parasitica,  defined,  loi,  103. 
Paria  aterrima,  212. 
Paris  green,  analysis  of,  434. 
Paroxya,  90. 

Parthenogenesis  in  plant-lice,  123. 
Passalus  cornutus,  197. 
Pea-weevils,  223. 
Peach-borer,  261. 

-louse,  134. 
Peacock-flies,  365. 
Pear-midge,  339. 

-psylla,  life  history,  137. 

sinuate  borer  in,  187. 

-slug,  372. 
Pectinated  antennae,  21. 
Peddlers,  222. 
Pediculus  species,  103. 
Pelecinus  polyturator,  389. 
Pelidnota  punctata,  202. 
Peloposus  species,  402. 
Pemphigus,  described,  132. 
Penis  of  insects,  47. 
Pentatomidse,  defined,  162. 
Pentilia  misella,  174. 
Pepsis  species,  401. 
Perception,  sense  of,  45. 
Periodical  cicada,  140. 
Periplaneta  orientalis,  82. 
Perlidae,  described,  64. 
Pernicious  scale,  118. 
Persian  insect  powder,  442. 
Pezotettix,  91. 
Phasmidae,  described,  84. 
Philampelus  achemon,  258. 

pandorus,  258. 
Phorbia  brassicae,  361. 

ceparum,  363. 
Phosphorus  against  roaches,  82. 
Photinus  pyralis,  190. 
Phthirius  inguinalis,  105. 
Phycitinae,  312. 
Phyllodromia  germanica,  82. 
Phyllcscus  flaviventris,  373. 
Phyllotreta  vittata,  221. 
Phylloxera,  life  history,  128. 


Phymata,  habits  of,  154. 
Phyniatodes  amcenus,  207. 

variabilis,  207. 

varius,  207. 
Physopoda,  101. 
Phytonomus  punctatus,  229. 
Phytophaga,  described,  205. 
Phytophagous  beetles,  defined,  165. 
Pickle-moth,  311. 
Pierinae,  246. 
Pieris  protodice,  248. 

rapae,  246. 
Pigeon  tremex,  375. 
I'impla  conquisitor,  381. 
Piophila  casei,  368. 
Pissodes  strobi,  230. 
Plagionotus  speciosus,  208. 
Plant-lice,  defined,  123. 

life  history,  124. 

on  roots,  127. 

remedies  against,  135. 
Planting,  date  of,  important,  428. 
Platyptera,  described,  64. 
Platysamia  cecropia,  280. 
Plecoptera,  described,  63. 
Pleurum  or  side,  25. 
Ploughing,     to     reduce     insect     injury, 

425- 
Plum  curculio,  232. 
Plume-moths,  318. 
Plumose  antennae,  21. 
Plusia  brassicae,  302. 

species,  302. 
Podurids,  56. 

Poecilocapsus  lincatus,  156. 
Poisers,  of  flies,  327. 
Polistes  species,  406. 
Pollen  basket,  408. 
Pollination,  due  to  bees,  408. 
Polyphemus  moth,  282. 
Pomace-flies,  367. 
Pompilidas,  400. 
Potash  as  a  winter  wash,  450. 
Potato-beetle,  old-fashioned,  225. 
striped,  213. 
three-lined,  211. 

flea-beetle,  219. 

stalk-borer,  234. 

scab-gnat,  335. 


478 


INDEX. 


Potato-sphinx,  256. 
Poultry-lice,  71. 
Powder  bellows,  455. 
Praying  Mantis,  habits  of,  84. 
Predaceous  bugs,  152. 

insects,  chapter  on,  418. 
Preventives,  chapter  on,  418,  430. 
Printers-ink  bands,  433. 
Prionidus  cristatus,  152. 
Prionoxystus  robiniae,  287. 
Prionus  laticollis,  206. 
ProctotrypidDg,  387. 
Prolegs,  defined,  12. 
Prominents,  275. 
Prothorax,  23. 
Protoparce  Carolina,  256. 

celeus,  256. 
Psenocorus  supernotatus,  208. 
Pseudo-neuroptera,  defined,  53,  54,  58. 
Pseudo-trachea  of  fly,  20. 
PsocidEe,  described,  68. 
Psocus  lineatus,  69. 
Psychidse,  273. 
Psychomorpha  epimenis,  264. 
Psylla  pyricola,  137. 
Psyllidje,  defined,  137. 
Pteromalus  puparum,  385. 
Pterophoridse,  318. 
Ptinidce,  193. 
Pubescent  antennas,  22. 
Pulvilli,  defined,  26. 
Pulvinaria  innumerabilis,  no. 
Pumps,  for  spraying,  456,  462. 
Punkies,  334. 
Pupa,  defined,  49. 
Pupipara,  369. 
Pyralididte,  310. 
Pyralis  farinalis,  312. 
Pyrausta  species,  311. 
Pyraustidos,  310. 

Pyrethro-kerosene  emulsion,  443. 
Pyrethrum  and  its  uses,  442. 
Pyrophila  pyramidoides,  299. 
Pyrrharctia  Isabella,  266. 

Quassia  as  an  insecticide,  453. 
Queen  bees,  415. 
Quince-borer,  209. 
-curculio,  234. 


Radish-maggot,  362. 
Raphidia,  72. 
Raptoria,  defined,  81. 
Raspberry,  Byturus,  180. 

-slug,  374. 
Rat-tailed  larvae,  350. 

how  they  breathe,  37. 
Raupenleim  and  dendrolene,  431. 
Receptaculum  seminis,  46. 
Rectum,  described,  30. 
Red-bug  on  cotton,  157. 

-humped  prominent,  277. 

-legged  locust,  go. 

-necked  cane-borer,  186. 
Reduviidce,  defined,  151. 
Reflowing  cranberry  bogs,  428. 
Regal  walnut-moth,  278. 
Reniform  spot,  289. 
Reproduction  among  insects,  45. 
Resin  washes,  use  and  formulas,  447. 
Respiration  in  insects,  33. 

in  dragon-fly  larvae,  51. 

in  water-beetles,  36. 

economic  bearing  of,  33,  38. 
Retina,  described,  41. 
Rhipiceridse,  182. 
Rhizobiinse,  described,  127. 
Rhizobius,  174. 
Rhopalocera,  defined,  241. 
Rhopobota  vacciniana,  320. 
Rhubarb,  weevil  on,  230. 
Rhynchophora,  165,  228. 
Rhynchophorus  palmarum,  236. 
Roaches,  life  history,  81. 
Robber-flies,  344. 
Rocky  Mountain  locust,  90. 
Root-lice,  remedies  for,  130. 

-maggots,  360. 

web-worms,  317. 
Rose-beetle,  Fuller's,  228. 

-bug,  199. 

-chafer,  199. 

leaf-hopper,  148. 

leaf-rollers,  321. 

-scale,  119. 

-slug,  374. 
Rosy  Dryocampa,  279. 
Rostrum,  defined,  17. 
Rotation,  use  of,  426. 


INDEX. 


479 


Round-headed  borers.  205. 
Rove-beetles,  172. 

Saliva  and  its  uses,  31. 
Salivary  glands,  30,  31. 
Saltatoria,  defined,  81. 
San  Jose  scale,  118. 
Sand-crickets,  97. 

-flies,  334. 
Sannina  exitiosa,  261. 
Sap-beetles,  181. 
Saperda  Candida,  209. 
Sarcophaga  carnaria,  355. 
Sarcopsylla,  species  of,  329. 
Saw-flics,  371. 
Scale  insects,  106. 

remedies  for,  108,  120. 
Scape  of  antenna,  22. 
Scavenger  beetles,  172,  197. 
Scaraba^idse,  197. 
Scenopinidas,  347. 
Scenopinus  fenestralis,  347. 
Schistocerca  americana,  89. 

peregrinum,  89. 
Schizoneura,  described,  133. 

lanigera,  133. 
Sciara  species,  334. 
Sclcrites,  defined,  23. 
Scoliidae,  400. 
Scolytidae,  237. 
Scolytus  rugulosus,  238. 
Scorpion  flies,  their  habits,  etc.,  tj. 
Screw-worm  fly,  357. 
Scudderia  species,  94. 
Scurfy  scale,  described,  119. 
Scutellerida;,  defined,  163. 
Scymnus  species,  174. 
Segments  in  insects,  311. 
Semi-loopers,  300. 
Seminal  receptacle,  46. 
Sensation  in  insects,  40. 
Sericaria  mori,  286. 
Serrate  antennae,  21. 
Serricornia,  defined,  165. 
Sesia  acerni,  262. 

tipuliformis,  263. 
Sesiidae,  259. 

Seventeen-year  locust,  140. 
Sex  in  insects,  46. 


Shecp-bot,  352. 

-tick,  369. 
Sialidae,  described,  72. 
Silk-worm,  286. 
Silpha  species,  171. 
SilphidcB,  171. 
Silvanus  surinamensis,  176. 
Silver-fish,  56. 
Simuliidoe,  341. 
Sinoxylon,  193. 
Sinuate  pear-borer,  187. 
Sitodrepa  panicea,  193. 
Skippers,  254. 

in  cheese,  368. 
Slugs,  beetle  larvae,  211. 

saw-fly  larvae,  372. 
Smell,  sense  of,  43. 

organs  of,  in  antennae,  20, 
Snake-doctors,  60. 
Snapping  beetles,  182. 
Snout-beetles,  described,  228. 

what  are,  165. 
Soap  mixtures,  how  they  kill,  38. 
Soaps  as  insecticides,  444. 
Social  bees,  414. 

life  among  Termites,  64. 

wasps,  405. 
Soft  scales,  described,  no. 
Soldier  beetles,  191. 

flies,  343. 
Solitary  bees,  407. 
Spanish  flies,  225. 
Span-worms,  307. 
Species,  defined,  52. 
Sphecidae,  defined,  402. 
Sphecius  speciosus,  403. 
Sphenophorus,  species  of  236. 
Sphex  ichneumonea,  403. 
Sphingidae,  254. 
Sphinx  Carolina,  256. 

celeus,  256. 
Spilosoma  virginica,  266. 
Spiracles,  described,  33. 

how  protected,  34. 
Spittle  insects,  146. 
Spraying  machinery,  456. 
Spring-beetles,  182. 

-tails,  53,  56. 
Spotted  vine-chafer,  202. 


48o 


INDEX. 


Squash-borer,  259. 

-bug,  160. 

lady-bird,  175. 
Stable-fly,  358. 
Stag-beetles,  196. 
Stagmomantis  Carolina,  84. 
Staphylinidas,  172. 
Stem-mother  in  plant-lice,  123. 
Stenopalmatus,  97. 
Sternum  or  breast,  25. 
Stinging  Hymenoptera,  390. 
Stomach  poisons,  how  they  act,  32. 
Stomoxys  calcitrans,  358. 
Stone-flies,  63. 

Stored  produce.  Termites  in,  67. 
Strategus,  203. 
Stratiomyidae,  343. 
Strawberry-root  borers,  212. 

weevil,  231. 
Stridulating  organs,  93. 
Striped  cucumber-beetle,  214. 
Structure  in  general,  11. 
Subterranean  forms,  breathing,  36. 
Sucking  lice,  103. 

mouth,  17, 
Sugar-cane  beetle,  203. 

borers,  317. 

Termite  injury  to,  67. 
Sulphur  as  an  insecticide,  452. 
Sutures,  defined,  23. 
Swallow-tail  butterflies,  250. 
Swarming  of  bees,  what  is,  415. 
Sweet-potato  flea-beetle,  219. 
tortoise-beetles,  222. 
Syrphidae,  347. 
Systena  blanda,  221. 

Tabanidae,  342. 
Tachina  flies,  354. 

vivida,  354. 
Tactile  organs,  what  are,  44. 
Tarantula  hawk,  401. 
Tarred  paper  against  borers,  431. 
Tarsus,  defined,  26. 
Taste  in  insects,  43. 
Tegmina,  defined,  79. 
Telea  polyphemus.  281. 
Telephorus,  191. 
Tendon,  described,  28. 


Tenebrionidae,  224. 

Tenebrioides,  182. 

Tent-caterpillars,  284. 

Tenthredinidae,  371. 

Teras  and  its  parasites,  420. 
minuta,  319. 

Termes  flavipes,  65,  67. 

Termites,  their  habits,  etc.,  64. 

Testes,  described,  47. 

Tettiginse,  described,  91. 

Thalessa  species,  379. 

Thecla,  species  of,  245. 

Thick-head  flies,  351. 

Thorax,  structure  and  function,  23. 

Three-lined  potato-beetle,  211. 

Thripidae,  defined,  loi. 

Thrips,  life  history,  102. 
remedies  for,  102. 

Thyridopteryx  ephemeraeformis,  273, 

Thysanoptera,  defined,  loi. 

Thysanura,  defined,  53,  54. 
chapter  on,  55. 

Tibia,  defined,  26. 
Tiger-beetles,  described,  166. 
Time  of  planting,  important,  428. 
Tingitidae,  defined,  154. 
Tinea  pellionella,  325. 
Tineina,  defined,  323. 
Tiphia  inornata,  400. 
Tipulidae,  330. 
Tobacco  and  its  uses,  440. 
against  root-lice,  131. 
beetle,  193. 
sphinx,  256. 
thrips  on,  102. 
Tomato  fruit-worm,  303. 
Tortoise  beetles,  222. 
Tortricids,  319. 
Touch  in  insects,  44. 
Tracheae,  described,  34. 
Tracheal  gills,  37. 
Tracheates,  defined,  34. 
Transformations,  how  observed,  50. 
Trap  crops,  428. 
Tree-crickets,  100. 
-hoppers,  138. 
Tremex  columba,  375. 
Tribolium  species,  225. 
Trichobaris  3-notata,  234. 


INDEX. 


481 


Trichogramma  prctiosa,  386. 
Trichoptera,  defined,  77. 
Triphleps  insidiosus,  156. 
Triungulin  of  meloid  larva,  227. 
Trochanter,  defined,  26. 

in  parasites,  379. 
Trogoderma,  179. 
Trogositidoe,  182. 
Trogus  exesorius,  381. 
lYox,  199. 

Trypeta  ponionella,  366. 
Tryxalinae,  described,  87. 
Tubulifera,  390. 
Tumble-bugs,  198. 
Turkey-gnat,  340. 
Turkeys  versus  grasshoppers,  427. 
Tussock  moths,  268. 
Twig-girdlers,  207,  210. 
Two-striped  tortoise  beetle,  222. 

Under-sprayers,  461. 
Uroceridae,  371,  374. 

Vagina,  described,  46. 
Valves  of  the  heart,  32. 
Vanessa  antiopa,  24^. 
Vaporer  moths,  268. 
Vapors  as  insecticides,  450. 
Vedalia  cardinalis,  173. 

versus  Icerya,  421. 
Velvet  ants,  400. 
Venation,  defined,  25. 
Vermipsylla,  species  of,  329. 
Vermorel  nozzle,  456. 
Vespa  species,  405,  406. 
Vespidse,  404. 
Vestiture  of  bees,  408. 
Viviparous  plant-lice,  123. 

scale  insects,  114. 
Vision  of  insects,  41,  42. 

Walking-leaves,  life  history,  85. 

-sticks,  life  history,  85. 
Washing  trees  in  winter,  433. 
Wasps  arc  beneficial,  407. 
Water  as  an  insecticide,  450. 

-beetles,  169. 


Water-boatman,  150. 

-scavengers,  170. 

-striders,  151. 
Wavy-striped  flea-beetle,  221. 
Waxy  scales,  108,  112. 
Web-worms,  266,  311,  317. 
Weevils,  defined,  228. 
Whale-oil  soap,  445. 
Wheat-head  army-worm,  296. 

Hessian  fly  in,  336. 

-midge,  338. 

saw-fly  borer,  376. 

stalk-borer,  299. 
Wheel-bug,  described,  152. 
White  ants,  life  history,  64. 

ermine  moth,  266. 

-faced  wasp,  406. 

-grubs,  196. 

-pine  weevil,  230. 
Whitewash,  usefulness  of,  422. 
Whirligig  beetles,  169. 
Willow  saw-fly,  374. 
Window  flies,  371. 
Winglet,  defined,  366. 
Wings,  number  and  location,  12. 

structure  of,  25. 
Wings  of  the  heart,  33. 
Winter  washing  of  fruit-trees,  433. 
Wire  netting  against  borers,  430. 
Wire-worms,  crane-fly  larvae,  331 
described,  182. 
remedies  for,  184. 
Woolly  apple-louse,  133. 

bears,  265. 

plant-lice,  133. 
Worker-ants,  391. 
Wrigglers,  332. 

Xiphidium  species,  96. 
Xylina  antennata,  300. 

species,  300. 
Xylocopa  virginica,  412. 
Xyloryctes,  203. 

Yellow-jackets,  405. 

-necked  caterpillar,  275. 

Zeuzera  pyrina,  287. 


31 


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